Subject: Fw: Further eruptions, lava flowage and tsunami at Stromboli.
From: "Erich Kern" efkern@.............
Date: Tue, 31 Dec 2002 17:43:57 -0800
-----Original Message-----
From: Dan Shackelford [mailto:danshack@..............
Sent: Tuesday, December 31, 2002 4:48 PM
To: gvn@............... mayberry@..............
Subject: Further eruptions, lava flowage and tsunami at Stromboli.
Following the strong explosion and lava flow production of 28 December at
Stromboli, the lava flows appeared to cease moving that day. However, by 30
December the lava flowage down the Sciara del Fuoco had resumed, although
at a slower rate than that of the 28th. At 1325 on the 30th there was
another strong explosion with a large amount of ash. A small tsunami also
occurred, likely the result of the collapse of part of the lava fields on
the Sciara del Fuoco (perhaps more than the lava flows collapsed, it is
unclear.). About 6 people were injured by the tsunami. There have been
voluntary evacuations from the island.
Source: http://www.educeth.ch/stromboli/beso/bes02c-en.html
31 December 2002, 8.30
Update: The tsunami phenomenon, which yesterday we defined "small" in order
to avoid useless alarms when news were still very confusing and
contradictory, has revealed hour after hour all its severity. The greatest
damages were recorded in Ginostra, but also in the village of Stromboli
many boats were destroyed or taken away by the waves, and many buildings
were damaged. At least 3 tourists are reported injured, and other sources
talk of 6 injured in total. The tsunami has reached also the other Eolian
islands and Milazzo harbour, where 2 tankers suffered difficulties. During
the evening, following the invitation of the Civil Defense, tens of
inhabitants and tourists voluntarily left the island. Moreover, since this
morning NON-RESIDENT PEOPLE ARE NOT ALLOWED TO LAND ON STROMBOLI.
For what concerns the dynamics of the phenomenon producing the tsunami,
there are no evidences of summit eplosions, but only of the collapse, as we
suggested yesterday, of part of the lava field over the steep slope of the
Sciara del Fuoco, that may have detached only by gravitational instability.
This hypothesis is supported by the observation, yesterday afternoon, of a
big scar at about midslope on the Sciara (source: the volcano guides
Antonio Famularo and Nino Zerilli) and by the seismic data recorded by INGV
- Catania, which show the presence of two non-volcanic seismic events, at
13:15 and 13:22 local time respectively.
30 December 2002, 14:55
Update: The village of Stromboli is currently without power supply,
probably because of a fault in the power engine, located close to the
coast. First damages to walls and buildings near the coast are reported,
due to the tsunami wave. Moreover, new ash-rich explosions are reported
near the Sciara, which suggests new interactions between magma and
seawater. A new survey of Civil Defense and INGV is currently in progress.
30 December 2002, 13.45
Update: A new, strong, explosion, observed at about 13:25 local time, has
ejected a great amount of ash that is now falling, mixed with rain, over
the village of Stromboli. The explosion must have caused a collapse of part
of the lava flow deposits (or more) along the Sciara del Fuoco, as a small
tsunami was observed all along the coast near the villages, from Ficogrande
(up to the road) to Scari (up to the helipad). Also in Ginostra boats were
moved by the tsunami in the small harbour. The explosion was apparently not
so loud, and no earthquake was felt by the population.
30. December 2002, 11.00
Update: According to the Stromboli volcano guides, and in particular to
Antonio Famularo, the lava flows resumed their movement after a pause,
although slower than the first day. The flows seem to originate from a
(new? different?) fissure, at about 800 m, below the NE crater. The flows
still reach the sea, producing a smaller amount of vapour with respect to
the beginning of the eruption. The lack of visibility at the top still
prevents observers from evaluating the level of strombolian activity at the
craters during the lava effusion.
28. December 2002
Abbreviated from report by Sonia Calvari, Istituto Nazionale di Geofisica e
Vulcanologia, via VOLCANO listserv: "On 28 December the height of ejecta
reached 200 m above NE Crater, and the shape of explosions suggested magma
very close to the crater rim. This activity climaxed at 18:30 with a strong
explosion that caused ash fallout on the village of Stromboli, accompanied
by the opening of an eruptive fissure trending NE-SW. The fissure opened at
the NE base of NE Crater. A lava flow came out from the base of the
fissure, and formed three lava branches spreading within the Sciara del
Fuoco. Within 30 minutes the flows reached the sea, about 1 km away. The
lava flows were up to 300 m wide at the shore line, but very narrow along
the steep slope of Sciara del Fuoco.
A thermal survey carried out from helicopter on 29 December did not allow
us to see the craters because of poor weather conditions. A thick cloud was
covering the summit of the volcano above 600 m a.s.l. The lava flows below
this elevation were cooling and did not show any movement, suggesting the
end of the effusive phase. Photos are on the INGV-CT web page."
o o o o o o o o > > > > > danshack@.............
o _____________________________
o _____ | |
.][__n_n_|DD[ ====_____ | |
>(________|__|_[_________]_|___________________________|
_/oo OOOOO oo` ooo ooo 'o!o!o o!o!o`
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re. Seismometer Distance Transducer
From: ChrisAtUpw@.......
Date: Wed, 1 Jan 2003 14:00:11 EST
Hi all seis experimenters,
John Lahr has very kindly put my notes on the LVDT precision seismic
sensor Kit on his Website at:
http://jjlahr.com/science/psn/chapman/lvdt/
Th introductory notes now include three close up Webcam photos of the
sensor and board. Click on any photo to get an enlarged image.
The Experimental notes include details of the modifications to reduce
the sensor noise and to greatly extend the period, with circuit diagrams and
components lists. I have been able to achieve a resolution of about +/-7 nano
metres and a sensor movement range of >+/-12 mm with this Kit.
I am developing additional LVDT applications circuits with inexpensive
sensors similar to those used by Sean Morrissey on his vertical STM-8 and
also with capacitative sensor plates. I will publish them in due course. The
NE5521 LVDT chip seems to be easy to use and to be capable of excellent
performance.
Please also look at my notes on Meredith's Website
http://geocities.com/meredithlamb/
Regards,
Chris Chapman
Hi all seis experimenters,
Th introductory notes now include three close up Webcam photos of the sensor and board. Click on any photo to get an enlarged image.
The Experimental notes include details of the modifications to reduce the sensor noise and to greatly extend the period, with circuit diagrams and components lists. I have been able to achieve a resolution of about +/-7 nano metres and a sensor movement range of >+/-12 mm with this Kit.
I am developing additional LVDT applications circuits with inexpensive sensors similar to those used by Sean Morrissey on his vertical STM-8 and also with capacitative sensor plates. I will publish them in due course. The NE5521 LVDT chip seems to be easy to use and to be capable of excellent performance.
Chris Chapman
Subject: Re: Re. Seismometer Distance Transducer
From: meredithlamb meredithlamb@.............
Date: Wed, 01 Jan 2003 15:33:55 -0700
Hi Chris and all,
Although I've not had any actual experience with LVDT's and their
circuits; it appears that your reference to the NE design and/or
your modifications look to be very highly encouraging for their
use in more precision instrumentation by amateurs. Thanks for
all the work you've done!!! I'd hazard to guess that with such,
one might find a really reasonably low priced sensor and
accurate assembly that has been not really obtainable heretofore!
About the only question of a general nature, I can find to ask
is that regarding the shielding of the LVDT unit. Roughly, what
do you use; or would suggest in either the minimum or maximum
sense? Would say, specific shielding surrounding the LVDT
board itself might be in itself somewhat adequate; as alot of
amateur seismo's are often rather huge?
Take care, Meredith Lamb
ChrisAtUpw@....... wrote:
> Hi all seis experimenters,
>
> John Lahr has very kindly put my notes on the LVDT precision
> seismic sensor Kit on his Website at:
> http://jjlahr.com/science/psn/chapman/lvdt/
>
> clipped......
Hi Chris and all,
Although I've not had any actual experience with LVDT's and their
circuits; it appears that your reference to the NE design and/or
your modifications look to be very highly encouraging for their
use in more precision instrumentation by amateurs. Thanks for
all the work you've done!!! I'd hazard to guess that with such,
one might find a really reasonably low priced sensor and
accurate assembly that has been not really obtainable heretofore!
About the only question of a general nature, I can find to ask
is that regarding the shielding of the LVDT unit. Roughly, what
do you use; or would suggest in either the minimum or maximum
sense? Would say, specific shielding surrounding the LVDT
board itself might be in itself somewhat adequate; as alot of
amateur seismo's are often rather huge?
Subject: Re: Re. Seismometer Distance Transducer
From: ChrisAtUpw@.......
Date: Wed, 1 Jan 2003 22:09:51 EST
In a message dated 01/01/2003, meredithlamb@............. writes:
> About the only question of a general nature, I can find to ask is that
> regarding the shielding of the LVDT unit. Roughly, what do you use; or
> would suggest in either the minimum or maximum sense? Would say, specific
> shielding surrounding the LVDT board itself might be in itself somewhat
> adequate; as a lot of amateur seismo's are often rather huge? Take care,
> Meredith Lamb
ChrisAtUpw@....... wrote: >
> >> Hi all seis experimenters, John Lahr has very kindly put my notes on the
>> LVDT precision seismic sensor Kit on his Website at:
>> http://jjlahr.com/science/psn/chapman/lvdt/
Hi Meredith,
The circuit is most sensitive to alternating magnetic fields with a
frequency harmonically related to the oscillator frequency. Screens of Al or
preferably tinplate are effective. It is preferable to make them with >6 cm
clearance from the ends of the board. If they are closer and can physically
move, they can couple to the sensor field and give a false reading. I checked
the overall frequency response of the sensor by fixing a single 1" square of
thick copper wire to the shaft of a miniature electric motor. I mounted the
loop about an inch from the outer end of one sensor coil and varied the
rotational rate of the motor to modulate the magnetic field.
The simplest way to check for interference is to wedge the ferrite rod
armature and check that the output signal is constant. The only interference
source that I experienced was due to the computer monitor several feet from
the sensor. Trimming the oscillator frequency removed the problem, additional
screening was a bonus. This sensitivity is only a problem if you don't know
about it.
Regards,
Chris Chapman
In a message dated 01/01/2003, meredithlamb@............. writes:
About the only question of a general nature, I can find to ask is that regarding the shielding of the LVDT unit. Roughly, what do you use; or would suggest in either the minimum or maximum sense? Would say, specific shielding surrounding the LVDT board itself might be in itself somewhat adequate; as a lot of amateur seismo's are often rather huge? Take care, Meredith Lamb
The circuit is most sensitive to alternating magnetic fields with a frequency harmonically related to the oscillator frequency. Screens of Al or preferably tinplate are effective. It is preferable to make them with >6 cm clearance from the ends of the board. If they are closer and can physically move, they can couple to the sensor field and give a false reading. I checked the overall frequency response of the sensor by fixing a single 1" square of thick copper wire to the shaft of a miniature electric motor. I mounted the loop about an inch from the outer end of one sensor coil and varied the rotational rate of the motor to modulate the magnetic field.
The simplest way to check for interference is to wedge the ferrite rod armature and check that the output signal is constant. The only interference source that I experienced was due to the computer monitor several feet from the sensor. Trimming the oscillator frequency removed the problem, additional screening was a bonus. This sensitivity is only a problem if you don't know about it.
Regards,
Chris Chapman
Subject: RE: Notes to UK--Nick
From: Jack Ivey ivey@..........
Date: Thu, 2 Jan 2003 09:33:24 -0500
Mauro,
I'm not sure it will be _very_ sensitive to axial movements. Horizontal
movements of the magnet will not cause as much change in magnetic
flux linkage through the coil as vertical movements because of the geometry
of the coil and magnet. For movement in one horizontal direction, the
magnet
is moving parallel to the wires at the top of the coil. For the other
horizontal
direction, the magnet is moving parallel to the flux between it's poles. In
either
case any flux change through the coil is a second order effect due to
curvature
of the coil and curvature of the magnet path. For vertical movement the
flux
change is a first order effect, proportional to displacement. As a guess I
would expect the horizontal sensitivity to be 5x to 10x down from the
vertical.
Jack
-----Original Message-----
From: Mauro Mariotti [mailto:mariotti@..........
Sent: Monday, December 30, 2002 2:01 PM
To: psn-l@..............
Subject: Re: Notes to UK--Nick
Hi all,
I suggest a different approach for homemade vertical sensors.
The sensor in the link you propose is VERY sensitive to axial movements
(horizontal movements)
if you give a look to
http://www.infoeq.it/doc02v_e.htm
and scroll the page until you reach:
Lacoste suspension sensor
you can see a good approach to a sensitive
long period seismometer.
There are also sofisticated tecniques to
have a virtually infinite response for that kind
of seismometer using a "zero length spring".
Mr Lacoste writed a lot of paper on it.
Chris Chapman is better documented on this point.
I hope to have the time to publish an abstract on these tecnmiques
but any clever mind can understand how the Lacoste suspension
is great and simple to build.
Regards
Mauro
----- Original Message -----
From: John & Jan Lahr
To: psn-l@..............
Sent: Monday, December 30, 2002 6:47 PM
Subject: Re: Notes to UK--Nick
I've scanned Jim's Short Period design plans and put a copy on my web site
here:
http://jjlahr.com/science/psn/lehman/
This will save on postage and make the plans available to more people. They
are a good example of how to document a seismic sensor design.
Happy New Year,
John
At 12:15 PM 12/28/2002, you wrote:
Nick--I do not need an e-mail address. I only needed your mailing address
to send the "Short Period" design plans.
The plans were mailed airmail to U.K. 2 days before Christmas.
A good New Year to you and all the PSN group.
J. Lehman.
Mauro,
I'm
not sure it will be _very_ sensitive to axial movements.
Horizontal
movements of the magnet will not cause as much change in magnetic
flux
linkage through the coil as vertical movements because of the
geometry
of the
coil and magnet. For movement in one horizontal direction, the
magnet
is moving parallel to the wires at the top of the
coil. For the other horizontal
direction, the magnet is moving parallel to the flux
between it's poles. In either
case any flux change through the coil is a second order
effect due to curvature
of the coil and curvature of the magnet
path. For vertical
movement the flux
change is a first order effect, proportional to
displacement. As a
guess I
would expect the horizontal
sensitivity to be 5x to 10x down from the
vertical.
Jack
-----Original Message----- From: Mauro Mariotti
[mailto:mariotti@.......... Sent: Monday, December 30, 2002 2:01
PM To: psn-l@.............. Subject: Re: Notes to
UK--Nick
Hi all,
I suggest a different approach for homemade
vertical sensors.
The sensor in the link you propose is VERY
sensitive to axial movements
I've scanned Jim's Short Period design plans and put a copy
on my web site here: http://jjlahr.com/science/psn/lehman/ This will save
on postage and make the plans available to more people. They are a
good example of how to document a seismic sensor design.
Happy New
Year, John
At 12:15 PM 12/28/2002, you wrote:
Nick--I do not
need an e-mail address. I only needed your mailing address to send
the "Short Period" design plans. The
plans were mailed airmail to U.K. 2 days before
Christmas. A good New Year to you and
all the PSN group.
J. Lehman.
Subject: Re: Notes to UK--Nick
From: "Mauro Mariotti" mariotti@.........
Date: Thu, 2 Jan 2003 16:15:35 +0100
Hi,
yes, I am gree.
The simple design of the lacoste suspension should be
considered instead of a simple vertical spring.
I experimented several solution and i what i learned
the Lacoste suspension is the easier and better solution
for a homemade design.
Anyway the interesting life of seismo-amateurs is the=20
ability to experiments many solutions...
so all the ideas are always welcome!
regards
Mauro
----- Original Message -----=20
From: Jack Ivey=20
To: psn-l@.................
Sent: Thursday, January 02, 2003 3:33 PM
Subject: RE: Notes to UK--Nick
Mauro,
I'm not sure it will be _very_ sensitive to axial movements. =
Horizontal
movements of the magnet will not cause as much change in magnetic=20
flux linkage through the coil as vertical movements because of the =
geometry
of the coil and magnet. For movement in one horizontal direction, the =
magnet
is moving parallel to the wires at the top of the coil. For the other =
horizontal
direction, the magnet is moving parallel to the flux between it's =
poles. In either
case any flux change through the coil is a second order effect due to =
curvature
of the coil and curvature of the magnet path. For vertical movement =
the flux=20
change is a first order effect, proportional to displacement. As a =
guess I=20
would expect the horizontal sensitivity to be 5x to 10x down from the =
vertical. =20
Jack
-----Original Message-----
From: Mauro Mariotti [mailto:mariotti@..........
Sent: Monday, December 30, 2002 2:01 PM
To: psn-l@..............
Subject: Re: Notes to UK--Nick
Hi all,
I suggest a different approach for homemade vertical sensors.
The sensor in the link you propose is VERY sensitive to axial =
movements
(horizontal movements)
if you give a look to=20
http://www.infoeq.it/doc02v_e.htm=20
and scroll the page until you reach:
Lacoste suspension sensor=20
you can see a good approach to a sensitive=20
long period seismometer.
There are also sofisticated tecniques to=20
have a virtually infinite response for that kind
of seismometer using a "zero length spring".
Mr Lacoste writed a lot of paper on it.
Chris Chapman is better documented on this point.
I hope to have the time to publish an abstract on these tecnmiques
but any clever mind can understand how the Lacoste suspension
is great and simple to build.
Regards
Mauro
----- Original Message -----=20
From: John & Jan Lahr=20
To: psn-l@.................
Sent: Monday, December 30, 2002 6:47 PM
Subject: Re: Notes to UK--Nick
I've scanned Jim's Short Period design plans and put a copy on my =
web site here:
http://jjlahr.com/science/psn/lehman/
This will save on postage and make the plans available to more =
people. They
are a good example of how to document a seismic sensor design.
Happy New Year,
John
At 12:15 PM 12/28/2002, you wrote:
Nick--I do not need an e-mail address. I only needed your =
mailing address to send the "Short Period" design plans.
The plans were mailed airmail to U.K. 2 days before =
Christmas.
A good New Year to you and all the PSN group.
J. Lehman.
Hi,
yes, I am gree.
The simple design of the lacoste =
suspension should=20
be
considered instead of a simple vertical =
spring.
I experimented several solution and i =
what i=20
learned
the Lacoste suspension is the easier =
and better=20
solution
for a homemade design.
Anyway the interesting life of =
seismo-amateurs is=20
the
I've scanned Jim's Short Period design plans and =
put a copy=20
on my web site here: http://jjlahr.com/science/psn/lehman/ This =
will=20
save on postage and make the plans available to more people. =
They are a good example of how to document a seismic sensor=20
design.
Happy New Year, John
At 12:15 PM=20
12/28/2002, you wrote:
Nick--I do not=20
need an e-mail address. I only needed your mailing address =
to send=20
the "Short Period" design plans. The=20
plans were mailed airmail to U.K. 2 days before=20
Christmas. A good New Year =
to you=20
and all the PSN group. &nbs=
p; =
; =20
J.=20
Lehman.
=
Subject: Re: Notes to UK--Nick
From: ChrisAtUpw@.......
Date: Thu, 2 Jan 2003 19:19:06 EST
In a message dated 02/01/2003, ivey@.......... writes:
> Mauro,
> I'm not sure it will be _very_ sensitive to axial movements. Horizontal
> movements of the magnet will not cause as much change in magnetic flux
> linkage through the coil as vertical movements because of the geometry of
> the coil and magnet. For movement in one horizontal direction, the magnet
> is moving parallel to the wires at the top of the coil. For the other
> horizontal direction, the magnet is moving parallel to the flux between
> it's poles. In either case any flux change through the coil is a second
> order effect due to curvature of the coil and curvature of the magnet path.
> For vertical movement the flux change is a first order effect,
> proportional to displacement. As a guess I would expect the horizontal
> sensitivity to be 5x to 10x down from the vertical.
> Jack
Hi Jack,
I am in agreement with your analysis so far as it goes, but it seems to
be incomplete and the conclusion may not be correct. The magnetic damping is
presumably adjusted to be near critical for vertical motion. This should also
give reasonably good damping for horizontal motion in the plane of the plate.
However, the plate will be only lightly damped for horizontal oscillations
perpendicular to it's plane and it will show a resonant characteristic with
enhanced swing amplitudes. The magnetic field is highly inhomogeneous and
movements of the magnet in this plane can be expected to give significant
induced signals. The sensitivity could be decreased by mounting the magnet
and sensor coil at right angles to the original orientation shown.
An arrangement which is less sensitive to horizontal motion and can give
a larger signal, may be made using a horizontally mounted flat coil with a
vertical cylindrical NdBFe magnet in the centre. A 1/2" dia by 1/2" long
magnet Type #13 from www.wondermagnet.com at $4 would be suitable. The end of
the polepiece should be about the centre plane of the coil. A suitable coil
would be about 3/8" long and 5/8" internal diameter, wound with 3,000 to
5,000 turns.
Neodymium magnets type #31 or #39 are capable of giving very high
damping forces, probably at considerably less cost than the 100 lb pull
damping magnets in the original design. I use two opposed #31s with a small
1/8" thick Al plate to critically damp a 1.1 kg pendulum. With very strong
cheap magnets readily available, we might as well make use of them.
Regards,
Chris Chapman
> >> From: Mauro Mariotti [mailto:mariotti@..........
>> Sent: Monday, December 30, 2002 2:01 PM
>> Subject: Re: Notes to UK--Nick
>> Hi all,
>> I suggest a different approach for homemade vertical sensors. The sensor
>> in the link you propose is VERY sensitive to axial movements
>> (horizontal movements) if you give a look to
>> http://www.infoeq.it/doc02v_e.htm
>> and scroll the page until you reach:
>> Lacoste suspension sensor
>> you can see a good approach to a sensitive long period seismometer.
>> .......
>> Regards Mauro
>>
>> >>> From: John & Jan Lahr
>>> I've scanned Jim's Short Period design plans and put a copy on my web
>>> site here: http://jjlahr.com/science/psn/lehman/
>>> This will save on postage and make the plans available to more people.
>>> They
>>> are a good example of how to document a seismic sensor design.
In a message dated 02/01/2003, ivey@.......... writes:
Mauro,
I'm not sure it will be _very_ sensitive to axial movements. Horizontal movements of the magnet will not cause as much change in magnetic flux linkage through the coil as vertical movements because of the geometry of the coil and magnet. For movement in one horizontal direction, the magnet is moving parallel to the wires at the top of the coil. For the other horizontal direction, the magnet is moving parallel to the flux between it's poles. In either case any flux change through the coil is a second order effect due to curvature of the coil and curvature of the magnet path. For vertical movement the flux change is a first order effect, proportional to displacement. As a guess I would expect the horizontal sensitivity to be 5x to 10x down from the vertical.
Jack
Hi Jack,
I am in agreement with your analysis so far as it goes, but it seems to be incomplete and the conclusion may not be correct. The magnetic damping is presumably adjusted to be near critical for vertical motion. This should also give reasonably good damping for horizontal motion in the plane of the plate. However, the plate will be only lightly damped for horizontal oscillations perpendicular to it's plane and it will show a resonant characteristic with enhanced swing amplitudes. The magnetic field is highly inhomogeneous and movements of the magnet in this plane can be expected to give significant induced signals. The sensitivity could be decreased by mounting the magnet and sensor coil at right angles to the original orientation shown.
An arrangement which is less sensitive to horizontal motion and can give a larger signal, may be made using a horizontally mounted flat coil with a vertical cylindrical NdBFe magnet in the centre. A 1/2" dia by 1/2" long magnet Type #13 from www.wondermagnet.com at $4 would be suitable. The end of the polepiece should be about the centre plane of the coil. A suitable coil would be about 3/8" long and 5/8" internal diameter, wound with 3,000 to 5,000 turns.
Neodymium magnets type #31 or #39 are capable of giving very high damping forces, probably at considerably less cost than the 100 lb pull damping magnets in the original design. I use two opposed #31s with a small 1/8" thick Al plate to critically damp a 1.1 kg pendulum. With very strong cheap magnets readily available, we might as well make use of them.
Regards,
Chris Chapman
From: Mauro Mariotti [mailto:mariotti@.......... Sent: Monday, December 30, 2002 2:01 PM Subject: Re: Notes to UK--Nick
Hi all,
I suggest a different approach for homemade vertical sensors. The sensor in the link you propose is VERY sensitive to axial movements
(horizontal movements) if you give a look to http://www.infoeq.it/doc02v_e.htm
and scroll the page until you reach: Lacoste suspension sensor
you can see a good approach to a sensitive long period seismometer.
........
Regards Mauro
From:John & Jan Lahr
I've scanned Jim's Short Period design plans and put a copy on my web site here: http://jjlahr.com/science/psn/lehman/
This will save on postage and make the plans available to more people. They
are a good example of how to document a seismic sensor design.
Subject: RE: Notes to UK--Nick
From: Jack Ivey ivey@..........
Date: Fri, 3 Jan 2003 09:01:08 -0500
Chris,
Good point about the lack of damping in one horizontal direction. Mauro's
web page shows a trace from a similar arrangement which shows
this (long tail of low amplitude oscillation after the earthquake signal).
I like the symmetry of your suggested coil setup, but I'm not sure
changing the coil orientation will fix the problem completely though. There
would still be undamped motion on one horizontal axis and still would be
some sensitivity of the coil/magnet to horizontal motion, although maybe
less than before.
If a horizontal damping plate with a vertically aligned magnetic field were
added it would help. The Wood-Anderson seismometers had a similar
problem with the torsion wire "twanging" and solved it with a drop of oil
around the wire as a damper.
Jack
-----Original Message-----
From: ChrisAtUpw@....... [mailto:ChrisAtUpw@........
Sent: Thursday, January 02, 2003 7:19 PM
To: psn-l@..............
Subject: Re: Notes to UK--Nick
In a message dated 02/01/2003, ivey@.......... writes:
Mauro,
I'm not sure it will be _very_ sensitive to axial movements. Horizontal
movements of the magnet will not cause as much change in magnetic flux
linkage through the coil as vertical movements because of the geometry of
the coil and magnet. For movement in one horizontal direction, the magnet
is moving parallel to the wires at the top of the coil. For the other
horizontal direction, the magnet is moving parallel to the flux between it's
poles. In either case any flux change through the coil is a second order
effect due to curvature of the coil and curvature of the magnet path. For
vertical movement the flux change is a first order effect, proportional to
displacement. As a guess I would expect the horizontal sensitivity to be 5x
to 10x down from the vertical.
Jack
Hi Jack,
I am in agreement with your analysis so far as it goes, but it seems to
be incomplete and the conclusion may not be correct. The magnetic damping is
presumably adjusted to be near critical for vertical motion. This should
also give reasonably good damping for horizontal motion in the plane of the
plate. However, the plate will be only lightly damped for horizontal
oscillations perpendicular to it's plane and it will show a resonant
characteristic with enhanced swing amplitudes. The magnetic field is highly
inhomogeneous and movements of the magnet in this plane can be expected to
give significant induced signals. The sensitivity could be decreased by
mounting the magnet and sensor coil at right angles to the original
orientation shown.
An arrangement which is less sensitive to horizontal motion and can
give a larger signal, may be made using a horizontally mounted flat coil
with a vertical cylindrical NdBFe magnet in the centre. A 1/2" dia by 1/2"
long magnet Type #13 from www.wondermagnet.com at $4 would be suitable. The
end of the polepiece should be about the centre plane of the coil. A
suitable coil would be about 3/8" long and 5/8" internal diameter, wound
with 3,000 to 5,000 turns.
Neodymium magnets type #31 or #39 are capable of giving very high
damping forces, probably at considerably less cost than the 100 lb pull
damping magnets in the original design. I use two opposed #31s with a small
1/8" thick Al plate to critically damp a 1.1 kg pendulum. With very strong
cheap magnets readily available, we might as well make use of them.
Regards,
Chris Chapman
From: Mauro Mariotti [mailto:mariotti@..........
Sent: Monday, December 30, 2002 2:01 PM
Subject: Re: Notes to UK--Nick
Hi all,
I suggest a different approach for homemade vertical sensors. The sensor in
the link you propose is VERY sensitive to axial movements
(horizontal movements) if you give a look to
http://www.infoeq.it/doc02v_e.htm
and scroll the page until you reach:
Lacoste suspension sensor
you can see a good approach to a sensitive long period seismometer.
........
Regards Mauro
From: John & Jan Lahr
I've scanned Jim's Short Period design plans and put a copy on my web site
here: http://jjlahr.com/science/psn/lehman/
This will save on postage and make the plans available to more people. They
are a good example of how to document a seismic sensor design.
Chris,
Good
point about the lack of damping in one horizontal direction. Mauro's
web
page shows a trace from a similar arrangement
which shows
this
(long tail of low amplitude oscillation after the
earthquake signal).
I like
the symmetry of your suggested coil setup, but I'm not sure
changing the coil orientation will fix the
problem completely though. There
would
still be undamped motion on one horizontal axis and still would
be
some
sensitivity of the coil/magnet to horizontal motion, although maybe
less
than before.
If a horizontal damping plate with a vertically
aligned magnetic field were
added
it would help. The Wood-Anderson seismometers had
a similar
problem with the torsion wire "twanging"
and solved it with a drop of oil
around
the wire as a damper.
Jack
-----Original Message----- From: ChrisAtUpw@.......
[mailto:ChrisAtUpw@........ Sent: Thursday, January 02, 2003 7:19
PM To: psn-l@.............. Subject: Re: Notes to
UK--Nick
In a message dated 02/01/2003,
ivey@.......... writes:
Mauro,
I'm not sure it will be _very_ sensitive to axial
movements. Horizontal movements of the magnet will not cause as much
change in magnetic flux linkage through the coil as vertical movements
because of the geometry of the coil and magnet. For movement in one
horizontal direction, the magnet is moving parallel to the wires at the top
of the coil. For the other horizontal direction, the magnet is moving
parallel to the flux between it's poles. In either case any flux
change through the coil is a second order effect due to curvature of the
coil and curvature of the magnet path. For vertical movement the flux
change is a first order effect, proportional to displacement. As a
guess I would expect the horizontal sensitivity to be 5x to 10x down from
the vertical. Jack
Hi
Jack,
I am in agreement with your analysis so
far as it goes, but it seems to be incomplete and the conclusion may not be
correct. The magnetic damping is presumably adjusted to be near critical for
vertical motion. This should also give reasonably good damping for horizontal
motion in the plane of the plate. However, the plate will be only lightly
damped for horizontal oscillations perpendicular to it's plane and it will
show a resonant characteristic with enhanced swing amplitudes. The magnetic
field is highly inhomogeneous and movements of the magnet in this plane can be
expected to give significant induced signals. The sensitivity could be
decreased by mounting the magnet and sensor coil at right angles to the
original orientation shown.
An arrangement
which is less sensitive to horizontal motion and can give a larger signal, may
be made using a horizontally mounted flat coil with a vertical cylindrical
NdBFe magnet in the centre. A 1/2" dia by 1/2" long magnet Type #13 from
www.wondermagnet.com at $4 would be suitable. The end of the polepiece should
be about the centre plane of the coil. A suitable coil would be about 3/8"
long and 5/8" internal diameter, wound with 3,000 to 5,000
turns.
Neodymium magnets type #31 or #39 are
capable of giving very high damping forces, probably at considerably less cost
than the 100 lb pull damping magnets in the original design. I use two opposed
#31s with a small 1/8" thick Al plate to critically damp a 1.1 kg pendulum.
With very strong cheap magnets readily available, we might as well make use of
them.
Regards,
Chris Chapman
From: Mauro Mariotti
[mailto:mariotti@.......... Sent: Monday, December 30, 2002 2:01
PM Subject: Re: Notes to UK--Nick
Hi all, I suggest a different approach for homemade vertical
sensors. The sensor in the link you propose is VERY sensitive to axial
movements (horizontal movements) if you give a look to
http://www.infoeq.it/doc02v_e.htm and scroll the page until you reach: Lacoste
suspension sensor you can see a good approach to a sensitive long
period seismometer. ....... Regards Mauro
From:John &
Jan Lahr I've scanned Jim's Short Period design plans and put a
copy on my web site here: http://jjlahr.com/science/psn/lehman/ This
will save on postage and make the plans available to more people.
They are a good example of how to document a seismic sensor
design.
Subject: Re: Graphite Levetation Devices
From: "Connie and Jim Lehman" lehmancj@...........
Date: Mon, 6 Jan 2003 22:38:16 -0500
Thanks Meredith for the summary of efforts at applying diamagnetic =
levitation techniques to seismic sensor possibilities. =20
I first saw a demonstration of diamagnetic levitation several =
summers ago in a Physics meeting. Later the details of that =
demonstration was published in the Dec. 2001, The Physics Teacher. We =
promptly built one from the recommended design, and were pleased at the =
ease of adjustment to achieve levitation. =20
To go from a simple demonstration to a stable seismic sensor is a =
challenge your summary addresses. I am still digesting the breadth of =
the article. Best wishes to all working on this quest..
=
Jim Lehman
Thanks Meredith for =
the summary=20
of efforts at applying diamagnetic levitation techniques to seismic =
sensor=20
possibilities.
I =
first saw a=20
demonstration of diamagnetic levitation several summers ago in a Physics =
meeting. Later the details of that demonstration was =
published in the=20
Dec. 2001, The Physics Teacher. We promptly built one from=20
the recommended design, and were pleased at the ease of adjustment =
to=20
achieve levitation.
To =
go from a=20
simple demonstration to a stable seismic sensor is a challenge your =
summary=20
addresses. I am still digesting the breadth of the article. =
Best=20
wishes to all working on this quest..
Subject: Re: Graphite Levitation Devices
From: meredithlamb meredithlamb@.............
Date: Mon, 06 Jan 2003 23:41:54 -0700
Hi Jim,
Thanks for the reference to the excellent illustrated pictures,
text and references of the Adobe PDF article; "Small Inexpensive
Diamagnetic Levitation Apparatus", at:
http://www.aapt.org/tpt/pdf/dec01/apparatus_dec01.pdf
It reminds me of the same type of mechanisms I used some
time back; even down to the same general hardware. The
current effort of several individuals is with levitating certain
varieties of graphite as the mass itself; a dramatic switch in the
roles of the basic material in the article above. Levitating magnets
just presents too much susceptibility to magnetic "noise", for much
useful seismometer utilization. Using levitated graphite as a recording
working seimometer has already been done by David Lamb and
James Spottiswoode.
There is more examples, text, and pictures of this approach on
John Lahr's very extensive and educational website, for those
interested. See:
http://www.jjlahr.com/science/physics/maglev/seismo/index.html
Thanks for the best wishes! Its been a rather "unknown", but
via the individual personal findings and discoveries of the fine
people involved, the exploration challenge is more fun than work.
Take care, Meredith
Connie and Jim Lehman wrote:
> Thanks Meredith for the summary of efforts at applying diamagnetic
> levitation techniques to seismic sensor possibilities. I first saw
> a demonstration of diamagnetic levitation several summers ago in a
> Physics meeting. Later the details of that demonstration was
> published in the Dec. 2001, The Physics Teacher. We promptly built
> one from the recommended design, and were pleased at the ease of
> adjustment to achieve levitation. To go from a simple demonstration
> to a stable seismic sensor is a challenge your summary addresses. I
> am still digesting the breadth of the article. Best wishes to all
> working on this
> quest..
> Jim Lehman
Hi Jim,
Thanks for the reference to the excellent illustrated pictures,
text and references of the Adobe PDF article; "Small Inexpensive
Diamagnetic Levitation Apparatus", at:
It reminds me of the same type of mechanisms I used some
time back; even down to the same general hardware. The
current effort of several individuals is with levitating certain
varieties of graphite as the mass itself; a dramatic switch in the
roles of the basic material in the article above. Levitating
magnets
just presents too much susceptibility to magnetic "noise", for much
useful seismometer utilization. Using levitated graphite as a
recording
working seimometer has already been done by David Lamb and
James Spottiswoode.
There is more examples, text, and pictures of this approach on
John Lahr's very extensive and educational website, for those
interested. See:
Thanks for the best wishes! Its been a rather "unknown", but
via the individual personal findings and discoveries of the fine
people involved, the exploration challenge is more fun than work.
Take care, Meredith
Connie and Jim Lehman wrote:
Thanks
Meredith for the summary of efforts at applying diamagnetic levitation
techniques to seismic sensor possibilities. I first saw
a demonstration of diamagnetic levitation several summers ago in a Physics
meeting. Later the details of that demonstration was published in
the Dec. 2001, The Physics Teacher. We promptly built one from the
recommended design, and were pleased at the ease of adjustment to achieve
levitation. To go from a simple demonstration to a stable
seismic sensor is a challenge your summary addresses. I am still
digesting the breadth of the article. Best wishes to all working
on this quest..
Jim Lehman
Subject: Volcan Baru Array Update
From: "a.rodriguez" stuff@.................
Date: Thu, 9 Jan 2003 12:55:10 -0500
Hello Everyone,
Happy New Year!
I have done some updates to the array site. It includes the work
done today. The eight bases are in place, within a few centimeters. Trenches
next.
http://www.volcanbaru.com/array/array.html
All comments wanted and welcome.
--
Best regards,
angel mailto:angel@..............
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: ebay item
From: BOB BARNS royb1@...........
Date: Fri, 10 Jan 2003 14:01:20 -0500
Hi, gang,
Ebay.com has an item which may be of interest.
Item # 3106334236 Ends Jan-15-03 15:51:29 PST
"This auction is for a United Electro Dynamics Type DR 273
seismograph/drum recorder. The unit has three servo motor driver pens
which write on a rotating lead screw driven drum in a continuous chart
from the top of the chart to the bottom."
This is three large drums on the same shaft.
Beware of the $95 crating charge.
Bob Barns
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: rockland filter
From: BOB BARNS royb1@...........
Date: Fri, 10 Jan 2003 14:12:32 -0500
Hi gang,
Another ebay item--
ROCKLAND WAVETEK 1042F DUAL HI LO FILTER
Item # 3104911183
Ends Jan-13-03 09:56:12 PST
These things are great with a seismograph, I use a 1022F which is v.
similar.
The manual should be avail. from Wavetek.
Bob Barns
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: ebay item
From: Raul Alvarez ralvarez@........
Date: Fri, 10 Jan 2003 13:22:43 -0700
Bob and group,
Be VERY AWARE that the "Packing charge" is in ADDITION to the "Shipping
charge" !!!!!!
RA
BOB BARNS wrote:
> Hi, gang,
>Ebay.com has an item which may be of interest.
> Item # 3106334236 Ends Jan-15-03 15:51:29 PST
>"This auction is for a United Electro Dynamics Type DR 273
>seismograph/drum recorder. The unit has three servo motor driver pens
>which write on a rotating lead screw driven drum in a continuous chart
>from the top of the chart to the bottom."
> This is three large drums on the same shaft.
>Beware of the $95 crating charge.
>Bob Barns
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
>
>
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: ebay item
From: meredithlamb meredithlamb@.............
Date: Fri, 10 Jan 2003 13:29:40 -0700
Hi Bob and all,
Nice of you to notify of seismo items Bob!
For this item, one might note that none of the pens are attached
to the pen motors. The original pens (likely were a heated stylus)
are probably hard to get and/or VERY expensive even "if" available.
Alternatively one might find/make ink pens, but it would also be
very difficult to do/find. The total item may have been a parts
salvage unit; which "may mean" other parts are also absent.
The pen drive amplifier and or any preamplifiere/filter aspect is
another additional problem that needs a solution with this. The
paper selection (heat sensitive and/or even ink paper) is also very
difficult to obtain for the width it "should" use.
Drum recorders have a fascinating visual appeal to the general
public.......but......it would likely be alot cheaper, and with
ALOT less hassle overall to go with a computer and A/D card
approach.
Take care, Meredith
BOB BARNS wrote:
> Hi, gang,
> Ebay.com has an item which may be of interest.
> Item # 3106334236 Ends Jan-15-03 15:51:29 PST
> "This auction is for a United Electro Dynamics Type DR 273
> seismograph/drum recorder. The unit has three servo motor driver pens
> which write on a rotating lead screw driven drum in a continuous chart
> from the top of the chart to the bottom."
> This is three large drums on the same shaft.
> Beware of the $95 crating charge.
> Bob Barns
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Fwd: USGS Press Release -- Scientists Update New Madrid Earthquake Forecasts
From: RLLaney@.......
Date: Mon, 13 Jan 2003 18:21:38 EST
Hi all:
Thought the group might be interested in this.
Bob Laney
Salem, Oregon
Hi all:
Thought the group might be interested in this.
Bob Laney
Salem, Oregon
News Release
U.S. Department of the Interior
U.S. Geological Survey
Release: Contact:
January 13, 2003 Eugene Schweig
Joan Gomberg
Address: Email:
3876 Central Ave . schweig@........
Suite 2 jgomberg@........
Memphis, TN 38152
Phone:
901-678-4974
901-678-4858
Scientists Update New Madrid Earthquake Forecasts
Scientists from the U.S. Geological Survey (USGS) and the Center for
Earthquake Research and Information at the University of Memphis have
updated their expectations for earthquakes in the New Madrid Seismic Zone.
The new forecasts estimate a 7 to 10 percent chance, in the next 50 years,
of a repeat of a major earthquake like those that occurred in 1811-1812,
which likely had magnitudes of between 7.5 and 8.0.
There is a 25 to 40 percent chance, in a 50-year time span, of a magnitude
6.0 or greater earthquake.
The earthquake probabilities in this region have changed considerably since
the most commonly cited forecast published in 1985. The new probabilities
show an increased chance of larger (7.5-8.0 magnitude) earthquakes and a
lesser chance of magnitude 6.0 and greater earthquakes. Meanwhile,
estimates of the hazard, or potential for damage caused by shaking, have
changed much less. A fact sheet with the new information is available on
the web at: http://pubs.usgs.gov/fs/fs-131-02/.
"More than fifteen years of research has given us the information to allow
us to update our forecasts. But even though the chances of a mid-sized
earthquake are reduced, the chances of a devastating earthquake in the
region have risen," said USGS scientist Eugene Schweig. "Given this new
information, people should absolutely not drop their guard. The threat of
an earthquake to Mid-America is still very real."
The New Madrid seismic zone is an area of frequent small earthquakes that
stretches along the lower Mississippi Valley from just west of Memphis,
Tennessee into southern Illinois. It also was the location of a sequence
of three or four major earthquakes in 1811 and 1812.
Major earthquakes in the range of magnitude 7.5 to 8.0 are capable of
causing widespread damage over a large region. Magnitude 6.0 earthquakes
can cause serious damage in areas close to the earthquake's epicenter
because the hazard (chance of damage in a given area) depends not only on
earthquake size, but also on where the earthquakes occur and local soil
conditions.
In Memphis and throughout the Mid-America region, the USGS is improving its
earthquake monitoring and reporting capabilities through the Advanced
National Seismic System (ANSS), a nation-wide network of modern strong
motion seismometers that can provide emergency-response personnel with
real-time "shaking" information within minutes of an earthquake.
ANSS stations assist emergency responders within minutes of an event
showing not only the magnitude and epicenter, but where damage is most
likely to have occurred.
Ten new ANSS instruments were recently installed in the Memphis area, 20
have been installed across the mid-America region, and more than 175 have
been installed in other vulnerable urban areas outside the central U.S. to
provide real-time information on how the ground responds when a strong
earthquake happens.
"The ultimate goal of ANSS is to save lives and ensure public safety," said
Dr. John Filson, U. S. Geological Survey (USGS) Earthquake Program
Coordinator. "This information, already available in Southern California,
is generated by data from seismic instruments installed in urban areas and
has revolutionized the response time of emergency managers to an
earthquake, but its success depends on further deployment of instruments in
other vulnerable cities."
In 1997, during the reauthorization of the National Earthquake Hazards
Reduction Program, Congress asked for an assessment of the status and needs
of earthquake monitoring. The result was the authorization of ANSS to be
implemented by the USGS. The system, when fully implemented, would
integrate all regional and national networks with 7,000 new seismic
instruments, including 6,000 new strong-motion sensors in 26 at-risk urban
areas. To date, approximately 350 instruments have been installed
nationwide.
New USGS National Seismic Hazard Maps depict these hazard or likelihood of
ground shaking. The USGS and its partners in universities and state
geological surveys are preparing more detailed hazard maps for Memphis and
other areas that include the effects of local soil conditions. For more
information see http://geohazards.cr.usgs.gov/eq/.
The goal of USGS earthquake monitoring is to mitigate risk - using better
instruments to understand the damage shaking causes and to provide
information to help engineers create stronger and sounder structures that
ensure vital infrastructures, utility, water, and communication networks
keep operating safely and efficiently.
As the Nation's science agency for natural resources, hazards and the
environment, the USGS is committed to meeting the health, safety and
knowledge needs of the changing world around us.
***www.usgs.gov***
Butch Kinerney
Public Affairs Specialist
USGS Office of Communications
703-648-4732
bkinerney@........
Subject: Something Happening??
From: "Jan D. Marshall" jandmarshall@............
Date: Wed, 15 Jan 2003 18:05:02 -0700
I am getting a lot of activity right now on my unit -- whats up??
1/15/03 23:57UTC
Jan Marshall
jandmarshall@............
http://myweb.cableone.net/jandmarshall/
Nampa, ID
I am =
getting a lot=20
of activity right now on my unit -- whats up??
1/15/03 =20
23:57UTC
Jan Marshall jandmarshall@............ http://myweb.cableone.net=
/jandmarshall/ Nampa, ID
Subject: Re: Something Happening??
From: Stephen & Kathy skmort@..........
Date: Wed, 15 Jan 2003 17:13:42 -0800
My alarm started going off at 21:51:37 near Pilot Hill Calif. USA
It is going to be a good sized one at a distance from me!!!
Stephen Mortensen
PSN Station #55
38.828N 120.979W
> "Jan D. Marshall" wrote:
>
> I am getting a lot of activity right now on my unit -- whats up??
>
> 1/15/03 23:57UTC
>
> Jan Marshall
> jandmarshall@............
> http://myweb.cableone.net/jandmarshall/
> Nampa, ID
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: Something Happening??
From: "Jan D. Marshall" jandmarshall@............
Date: Wed, 15 Jan 2003 18:28:12 -0700
well its time here was actually 00:57:30 UTC Lat 43.5462459
Long -116.5470666
Jan Marshall
jandmarshall@............
http://myweb.cableone.net/jandmarshall/
Nampa, ID
-----Original Message-----
From: psn-l-request@..............
[mailto:psn-l-request@................. Behalf Of Stephen & Kathy
Sent: Wednesday, January 15, 2003 6:14 PM
To: psn-l@..............
Subject: Re: Something Happening??
My alarm started going off at 21:51:37 near Pilot Hill Calif. USA
It is going to be a good sized one at a distance from me!!!
Stephen Mortensen
PSN Station #55
38.828N 120.979W
> "Jan D. Marshall" wrote:
>
> I am getting a lot of activity right now on my unit -- whats up??
>
> 1/15/03 23:57UTC
>
> Jan Marshall
> jandmarshall@............
> http://myweb.cableone.net/jandmarshall/
> Nampa, ID
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: OOPS Something Happening??
From: Stephen & Kathy skmort@..........
Date: Wed, 15 Jan 2003 17:31:20 -0800
OOPs,,, for some unknown reason my recording time is about 4 hours off????
Sooooo,, ignore the posted time on my last email,, I had a blue screen when I
checked, after the alarm, but didn't realize it had affected my recording as it
was still going when I cleared the screen!!!
Sorry,
Stephen
> "Jan D. Marshall" wrote:
>
> I am getting a lot of activity right now on my unit -- whats up??
>
> 1/15/03 23:57UTC
>
> Jan Marshall
> jandmarshall@............
> http://myweb.cableone.net/jandmarshall/
> Nampa, ID
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Something Happening??
From: Seisguy@.......
Date: Wed, 15 Jan 2003 20:41:30 EST
well, there is an event on the anza network that occured at 00:56 UTC.
M3.1 near Pomona. No other sites have it posted.
http://eqinfo.ucsd.edu/current_earthquakes/anza/regional.html
Mike O'Bleness
Palm Springs, CA
well, there is an event on the anza network that occured at 00:56 UTC.
Mike O'Bleness
Palm Springs, CA
Subject: Re: Something Happening??
From: Stephen & Kathy skmort@..........
Date: Wed, 15 Jan 2003 18:06:32 -0800
FYI,, looking at the world webicorders, Alaska and New Mexico have about the
same starting time with Texas and Hawaii a little behind that,, based on that,
my first guess would put it in lower Alaska, south western Canada, area???? If
so, it could be in the 6 to 7 range.
Stephen
38.828N 120.979W
Seisguy@....... wrote:
>
> well, there is an event on the anza network that occured at 00:56 UTC.
>
> M3.1 near Pomona. No other sites have it posted.
>
> http://eqinfo.ucsd.edu/current_earthquakes/anza/regional.html
>
> Mike O'Bleness
> Palm Springs, CA
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Something Happening??
From: meredithlamb meredithlamb@.............
Date: Wed, 15 Jan 2003 22:32:51 -0700
Jan,
Nice record you have on the Oregon quake at:
http://24.116.175.108/live%20data.htm
Perhaps (?), their was a after shock ~ 0520 UTC (?), but,
it might be much further away.
Like the marble base, and pics at:
http://24.116.175.108/Over%20all%20pictures.htm
Take care, Meredith
"Jan D. Marshall" wrote:
> well its time here was actually 00:57:30 UTC Lat 43.5462459
> Long -116.5470666
>
> Jan Marshall
> jandmarshall@............
> http://myweb.cableone.net/jandmarshall/
> Nampa, ID
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Fwd: Problems with Earthquake Data
From: John & Jan Lahr johnjan@........
Date: Thu, 16 Jan 2003 20:58:57 -0700
Does anyone live close enough to Eldon, Missouri, to give
this teacher a hand?
Thanks,
John Lahr
USGS
Golden, CO
http://jjlahr.com/science/
>------------- Begin Forwarded Message -------------
>
>Mailing-List: contact irised-help@.................. run by ezmlm
>X-No-Archive: yes
>List-Post:
>List-Help:
>List-Unsubscribe:
>List-Subscribe:
>Delivered-To: mailing list irised@.................
>From: Drmuloc@.......
>Date: Thu, 16 Jan 2003 13:12:46 EST
>Subject: Problems with Earthquake Data
>To: irised@.................
>
>I'm the science teacher in Eldon Missouri that is having major problems with
>her seismograph. Is there anyone out there who is close by that can help me
>set up a seismograph that doesn't record the pitter patter of anxious middle
>school children as they cross the concrete floor?
>
>I have had the computer person get us on line. I have my program set up. I
>just want someone to come to the school and tutor me for 30 minutes to an
>hour. They also need to look at my computer to see if everything is correct.
> Is this possible?
>
>My husband says that everything is correct on the computer (He is a Nuclear
>Physicist-Adjunct Proff.) Somehow, I cannot get his interpretations about
>how to run this equipment properly into my learning curve.
>
>My principal says that she will send me to wherever I need to go to learn
>everything, but I hate to go to far because I don't like to be out of the
>classroom.
>
>Thanks,
>
>M. A. Martin
>
>------------- End Forwarded Message -------------
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Subject: RE: Problems with Earthquake Data
From: steve hammond shammon1@.............
Date: Thu, 16 Jan 2003 21:42:23 -0800
Hi John, I'll be happy to supply ongoing mentoring help via the Internet if you can't find somebody closer.
Regards, Steve Hammond
-----Original Message-----
From: John & Jan Lahr [SMTP:johnjan@.........
Sent: Thursday, January 16, 2003 7:59 PM
To: psn-l@..............
Subject: Fwd: Problems with Earthquake Data
Does anyone live close enough to Eldon, Missouri, to give
this teacher a hand?
Thanks,
John Lahr
USGS
Golden, CO
http://jjlahr.com/science/
>------------- Begin Forwarded Message -------------
>
>Mailing-List: contact irised-help@.................. run by ezmlm
>X-No-Archive: yes
>List-Post:
>List-Help:
>List-Unsubscribe:
>List-Subscribe:
>Delivered-To: mailing list irised@.................
>From: Drmuloc@.......
>Date: Thu, 16 Jan 2003 13:12:46 EST
>Subject: Problems with Earthquake Data
>To: irised@.................
>
>I'm the science teacher in Eldon Missouri that is having major problems with
>her seismograph. Is there anyone out there who is close by that can help me
>set up a seismograph that doesn't record the pitter patter of anxious middle
>school children as they cross the concrete floor?
>
>I have had the computer person get us on line. I have my program set up. I
>just want someone to come to the school and tutor me for 30 minutes to an
>hour. They also need to look at my computer to see if everything is correct.
> Is this possible?
>
>My husband says that everything is correct on the computer (He is a Nuclear
>Physicist-Adjunct Proff.) Somehow, I cannot get his interpretations about
>how to run this equipment properly into my learning curve.
>
>My principal says that she will send me to wherever I need to go to learn
>everything, but I hate to go to far because I don't like to be out of the
>classroom.
>
>Thanks,
>
>M. A. Martin
>
>------------- End Forwarded Message -------------
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__________________________________________________________
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Subject: Software for the Earthscope
From: el.pillan@...........
Date: Fri, 17 Jan 2003 13:50:23 +0100 (CET)
Does anyone know any software compatible with the Earthscope (PS2) from
Kinemetrics?
Many thanks in advance for any suggestions you might have.
Kind regards from Germany,
Werner Keller / www.povi.org
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Software for the Earthscope
From: ChrisAtUpw@.......
Date: Fri, 17 Jan 2003 14:44:57 EST
In a message dated 17/01/03, el.pillan@........... writes:
> Does anyone know any software compatible with the Earthscope (PS2) from
> Kinemetrics?
>
>
Hi Werner,
Looking at http://www.kinemetrics.com/earthscope.html Kinemetrics are
supposed to supply a complete suite of software, 2 MB in all. The sensor is
vertical 1 to 30 Hz and seems to have an 18 bit A/D. It does not record
precise timing and is provided with 4 m of cable to connect to a com port of
the host computer.
Regards,
Chris Chapman
In a message dated 17/01/03, el.pillan@........... writes:
Does anyone know any software compatible with the Earthscope (PS2) from
Kinemetrics?
Werner Keller / www.povi.org
Hi Werner,
Looking at http://www.kinemetrics.com/earthscope.html Kinemetrics are supposed to supply a complete suite of software, 2 MB in all. The sensor is vertical 1 to 30 Hz and seems to have an 18 bit A/D. It does not record precise timing and is provided with 4 m of cable to connect to a com port of the host computer.
Regards,
Chris Chapman
Subject: BIG Quake
From: David A Nelson davenn@...............
Date: Mon, 20 Jan 2003 21:13:32 +1100
hi all
A magnitude 7.5 earthquake IN THE SOLOMON ISLANDS has occurred at:
10.42S 160.70E Depth 33km Mon Jan 20 08:43:06 2003 UTC
cheers
Dave N
In God I trust; All others pay cash :)
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Subject: Colorado School of Mines Seismometer Competition
From: John & Jan Lahr johnjan@........
Date: Mon, 20 Jan 2003 08:39:28 -0700
During the Fall of 2002 the freshmen at the Colorado School of Mines worked on
designing of an inexpensive seismic system. The details are given here:
http://www.jjlahr.com/science/psn/epics/
In December the best designs were selected and some of the students'
reports are
posted here:
http://www.jjlahr.com/science/psn/epics/reports/
I will continue to add reports as I receive them.
Although none of the designs are ready to go as it, some of the teams are
continuing to make refinements this semester. Over all this was a great
educational exercise, as the students have a gained a greater appreciation of
the difficulty of designing and then building a sensitive instrument. Also
as they continue at CSM, they will learn how useful their math, physics,
and engineering courses would have been had they taken them prior to
trying to build a seismometer! In their senior year, all of the CMS students
select an engineering project to work on. I'm hoping that for some the
challenge
of designing an inexpensive seismic sensor will remain, and that they
will apply their newly acquired skills to this topic once again.
Cheers,
John Lahr
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Subject: Acouple neodymium magnets sellers noted
From: meredithlamb meredithlamb@.............
Date: Mon, 20 Jan 2003 15:38:16 -0700
Hi all,
One might note that a canadian seller has a fair variety of
magnets at what appears to be at quite reasonably priced
items....and they appear to be quite below U.S. prices. Most
magnets seem to be gauss rated at MGOe of 38 which is alittle
above the (gauss) ratings of alot of normally available magnets.
I would guess the shipping costs will kick up the overall price
somewhat higher for country to country deliveries, obviously.
The E-Bay store name is: Hamilton Core Drill Bits
http://www.stores.ebay.com/id=14430047
His E-Bay feedback looks to be exceptionally good; with 647
positives, 10 neutrals, and zero negative. We've no idea if
he may offer other magnets in the future or this is a one time
deal. I've no prior personal experience with this seller.
Most items are only offered within the next two days or so.
Theres quite a variety of sizes. So, if you've been waiting for
a certain size to fit that certain sized seismo coil, or project
.....this "might" be the ticket for you.
*************
There is also another new neo mag seller that has a variety of
magnets within the U.S. His web site is at:
http://www.engconcepts.net/Magnets/Magnets.htm
The gauss ratings of the magnets vary, as does the sizes and
shapes he has; but I would say the prices are also fairly
reasonable. I've no prior personal experience with this seller.
***********
Perhaps now the increased ratings and sizes of the available
neo magnets are becoming less expensive than in the past...
which is very good.
Take care, Meredith
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Ref: More Diamagnetism
From: "Connie and Jim Lehman" lehmancj@...........
Date: Mon, 20 Jan 2003 22:28:26 -0500
PSN people---those interested in diamagnetism and possible seismic =
sensor applications may find the recent article in Feb. '03, "The =
Physics Teacher" helpful----a horizontal version of the previous =
vertical design---
Jim Lehman=20
PSN people---those =
interested=20
in diamagnetism and possible seismic sensor applications may find =
the=20
recent article in Feb. '03, "The Physics Teacher" helpful----a =
horizontal=20
version of the previous vertical design---
&nbs=
p; =
; =
=20
Jim Lehman
Subject: Re: Ref: More Diamagnetism
From: John & Jan Lahr johnjan@........
Date: Mon, 20 Jan 2003 21:53:24 -0700
Another aspect of the Physics Teacher article was demonstrating that
water was
diamagnetic (repelled by a magnet). I've posted a page in which
I've managed to
recreate the demonstration: http://jjlahr.com/science/physics/diamag/water/
Cheers,
John
At 08:28 PM 1/20/2003, you wrote:
PSN people---those
interested in diamagnetism and possible seismic sensor applications may
find the recent article in Feb. '03, "The Physics Teacher"
helpful----a horizontal version of the previous vertical
design---
Jim Lehman
Subject: Re: Ref: More Diamagnetism
From: meredithlamb meredithlamb@.............
Date: Mon, 20 Jan 2003 22:26:12 -0700
Hi Jim,
Thanks (!) for the reference too:
http://ojps.aip.org/tpt/
For those curious, click on February 2003, and go to "More
Diamagnetism Demonstrations" written by Chris Conery. It has
either standard HTML or Adobe PDF versions available.
I note they use some of the best diamagnetic pyrolytic graphite
known and likely their levitated magnet is also highly rated at
a MGOe of very likely 45. It "used to be" that this pyrolytic
graphite could only be obtained at a very high cost (~$400, for a
6" x 6" x ~ .1" thick piece!). They DO take a unusual
step with using the ceramic magnets, to the sides of the levitated
magnet.....one could use a single magnet that is height adjustable
(although this might be somewhat in the way of the view of the
surface). The fluid actually helps the magnet levitate higher than
normal.
Their approach actually seems to entail a number of additional
items to produce the same effect that John Lahr's considerably
more simplified version demonstrates. See:
http://jjlahr.com/science/physics/diamag/water/
Actually, this water diamagnetism hasn't heretofore been as
well demonstrated as via these 2 web sites that I'am aware
of. The newer and better material available has made some
of these demonstration units much more feasible to do, or try.
Congratulations to the innovative builders!
Take care, Meredith Lamb
Connie and Jim Lehman wrote:
> PSN people---those interested in diamagnetism and possible seismic
> sensor applications may find the recent article in Feb. '03, "The
> Physics Teacher" helpful----a horizontal version of the previous
> vertical design--- Jim Lehman
Hi Jim,
For those curious, click on February 2003, and go to "More
Diamagnetism Demonstrations" written by Chris Conery. It has
either standard HTML or Adobe PDF versions available.
I note they use some of the best diamagnetic pyrolytic graphite
known and likely their levitated magnet is also highly rated at
a MGOe of very likely 45. It "used to be" that this pyrolytic
graphite could only be obtained at a very high cost (~$400, for a
6" x 6" x ~ .1" thick piece!). They DO take a unusual
step with using the ceramic magnets, to the sides of the levitated
magnet.....one could use a single magnet that is height adjustable
(although this might be somewhat in the way of the view of the
surface). The fluid actually helps the magnet levitate higher
than
normal.
Their approach actually seems to entail a number of additional
items to produce the same effect that John Lahr's considerably
more simplified version demonstrates. See:
Actually, this water diamagnetism hasn't heretofore been as
well demonstrated as via these 2 web sites that I'am aware
of. The newer and better material available has made some
of these demonstration units much more feasible to do, or try.
Congratulations to the innovative builders!
Take care, Meredith Lamb
Connie and Jim Lehman wrote:
PSN
people---those interested in diamagnetism and possible seismic sensor applications
may find the recent article in Feb. '03, "The Physics Teacher" helpful----a
horizontal version of the previous vertical design---
Jim Lehman
Subject: Re: Ref: More Diamagnetism
From: ChrisAtUpw@.......
Date: Tue, 21 Jan 2003 08:40:55 EST
In a message dated 21/01/03, meredithlamb@............. writes:
> Hi Jim, Thanks (!) for the reference too: http://ojps.aip.org/tpt/ For those
> curious, click on February 2003, and go to "More Diamagnetism
> Demonstrations" written by Chris Conery. It has either standard HTML or
> Adobe PDF versions available. I note they use some of the best diamagnetic
> pyrolytic graphite known and likely their levitated magnet is also highly
> rated at a MGOe of very likely 45. It "used to be" that this pyrolytic
> graphite could only be obtained at a very high cost (~$400, for a 6" x 6" x
> ~ .1" thick piece!). They DO take a unusual step with using the ceramic
> magnets, to the sides of the levitated magnet.....one could use a single
> magnet that is height adjustable (although this might be somewhat in the
> way of the view of the surface). The fluid actually helps the magnet
> levitate higher than
>
Hi Meredith,
I get an 'We can not find the file....' when I click on the above. If
you copy the text to Web Address it works, but you then need to click on
'Papers'.
Ceramic magnets have relatively low fields and are quite temperature
sensitive. They are often fitted with soft iron cap plates to enable the
field to be concentrated, such as in loudspeaker applications.
Regards,
Chris Chapman
In a message dated 21/01/03, meredithlamb@............. writes:
Hi Jim, Thanks (!) for the reference too: http://ojps.aip.org/tpt/ For those curious, click on February 2003, and go to "More Diamagnetism Demonstrations" written by Chris Conery. It has either standard HTML or Adobe PDF versions available. I note they use some of the best diamagnetic pyrolytic graphite known and likely their levitated magnet is also highly rated at a MGOe of very likely 45. It "used to be" that this pyrolytic graphite could only be obtained at a very high cost (~$400, for a 6" x 6" x ~ .1" thick piece!). They DO take a unusual step with using the ceramic magnets, to the sides of the levitated magnet.....one could use a single magnet that is height adjustable (although this might be somewhat in the way of the view of the surface). The fluid actually helps the magnet levitate higher than
normal.
Hi Meredith,
I get an 'We can not find the file....' when I click on the above. If you copy the text to Web Address it works, but you then need to click on 'Papers'.
Ceramic magnets have relatively low fields and are quite temperature sensitive. They are often fitted with soft iron cap plates to enable the field to be concentrated, such as in loudspeaker applications.
Regards,
Chris Chapman
Subject: Re: Ref: More Diamagnetism
From: meredithlamb meredithlamb@.............
Date: Tue, 21 Jan 2003 11:05:40 -0700
Hi Chris,
John Lahr noted this web address correction:
http://ojps.aip.org/journals/doc/PHTEAH-ft/vol_41/iss_2/74_1-div0.html
He also noted that links for other versions are on this page:
http://ojps.aip.org/dbt/dbt.jsp?KEY=PHTEAH&Volume=CURVOL&Issue=CURISS
The "Physics Teacher" server seems to be quite slow to respond.
I agree on your magnets statement; and....yes, they may need a
added mechanical arrangement for the temperature ranges
changes that can occur. For that "general" arrangement, only
a temperature change of only afew degrees can have a big
levitation height change in position.
Your iron sheet add-on idea with other diamagnetic setups
involving seismic designs is quite a excellent and dramatic
improvement, where its possible to do so.
Take care, Meredith
ChrisAtUpw@....... wrote:
>
> Hi Meredith,
>
> I get an 'We can not find the file....' when I click on the
> above. If you copy the text to Web Address it works, but you then need
> to click on 'Papers'.
> Ceramic magnets have relatively low fields and are quite
> temperature sensitive. They are often fitted with soft iron cap plates
> to enable the field to be concentrated, such as in loudspeaker
> applications.
>
> Regards,
>
> Chris Chapman
Hi Chris,
The "Physics Teacher" server seems to be quite slow to respond.
I agree on your magnets statement; and....yes, they may need a
added mechanical arrangement for the temperature ranges
changes that can occur. For that "general" arrangement, only
a temperature change of only afew degrees can have a big
levitation height change in position.
Your iron sheet add-on idea with other diamagnetic setups
involving seismic designs is quite a excellent and dramatic
improvement, where its possible to do so.
Take care, Meredith
ChrisAtUpw@....... wrote:
Hi Meredith,
I get an 'We can not find the file....' when I click on the above. If you
copy the text to Web Address it works, but you then need to click on 'Papers'.
Ceramic magnets have relatively low fields and are quite temperature sensitive.
They are often fitted with soft iron cap plates to enable the field to
be concentrated, such as in loudspeaker applications.
Regards,
Chris Chapman
Subject: SPAM from my E-mail address
From: Bob Fryer bfryer@............
Date: Tue, 21 Jan 2003 13:53:19 -0800
Hello friends,
I am getting "rejected E-mails" from Mail Delivery System
and others. The items
from Mail Delivery System are 105 k in length, suggesting that the
original is about 100 k.
The addressees are often unknown to me, and are about subjects that I
have never hear of.
If you have any doubts about the subject... do not open the E-mail.
The good news is that, since I work on a Mac, it does not seem that a
virus is involved. I suspect that they picked picked up my address
from my websites.
Until this ceases, my E-mail Subject: lines will contain my initials, BF.
I apologize for any difficulty you may experience because of these
mental cretins.
Take care,
Bob Fryer
--
earthquake WARNING research
Animals, People, Scientific Evidence
www.earthquakewarning.org
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Subject: Large Quake rolling in now
From: Jeff Batten jeff.batten@........
Date: Tue, 21 Jan 2003 18:22:10 -0800
Picking up a large event. Looks very large. No one felt it in S cal.
Jeff
Jeff Batten
Electronics Technician III
CSUN Physics and Astronomy
San Fernando Observatory
818-677-2768
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Subject: Re: Large Quake rolling in now
From: DGentry509@.......
Date: Tue, 21 Jan 2003 21:33:05 EST
Mexico City 7.6 as reported by FCN at 1830 PST.
D Gentry
Mexico City 7.6 as reported by FCN at 1830 PST.
D Gentry
Subject: hi 3.2
From: allan egleston allane@.........
Date: Tue, 21 Jan 2003 18:34:09 -0800
A 3.2 event just occured 6 miles of Cabazon Ca
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Subject: Re: Large Quake rolling in now
From: "Larry Cochrane" cochrane@..............
Date: Tue, 21 Jan 2003 18:35:13 -0800
Looks like a magnitude of ~ Ms7.4 off of the coast of Mexico. This is based
on information from my sensors and a few of the broadband sensors I am
monitoring.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Jeff Batten"
To:
Sent: Tuesday, January 21, 2003 6:22 PM
Subject: Large Quake rolling in now
>
>
>
> Picking up a large event. Looks very large. No one felt it in S cal.
>
> Jeff
> Jeff Batten
> Electronics Technician III
> CSUN Physics and Astronomy
> San Fernando Observatory
> 818-677-2768
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
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Subject: Re: Large Quake rolling in now
From: Dgw5319@.......
Date: Tue, 21 Jan 2003 21:36:02 EST
Looks like maybe off the coast of Mexico? M 6.4+
EMSC Real Time SeismicityRedPuma Global List and Waveforms
Dave
Looks like maybe off the coast of Mexico? M 6.4+
Dave
Subject: hi update
From: allan egleston allane@.........
Date: Tue, 21 Jan 2003 18:39:11 -0800
mag 7 in mexico
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Subject: Re: Large Quake rolling in now
From: meredithlamb meredithlamb@.............
Date: Tue, 21 Jan 2003 19:40:52 -0700
Hi Jeff and all,
Yes indeed! Monitor here in Denver, totally "smeared" with
signal for ~ 10 minutes. Dangerious quake.
Just for interest, I had a undampened diamagnetic seismo setup
on the kitchen table (very solid, very little deflection upon
approach), and its pendulum was oscillating with about 1" of
lateral horizontal travel. Kind of rare to visually observe
such.
Take care, Meredith
Jeff Batten wrote:
> Picking up a large event. Looks very large. No one felt it in S cal.
>
> Jeff
> Jeff Batten
> Electronics Technician III
> CSUN Physics and Astronomy
> San Fernando Observatory
> 818-677-2768
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: mexico quake
From: TESMECO@.......
Date: Tue, 21 Jan 2003 21:57:45 EST
looks like a 7.6 no damage reports yet
not felt in riverside ca
looks like a 7.6 no damage reports yet
not felt in riverside ca
Subject: Mexico quake
From: meredithlamb meredithlamb@.............
Date: Tue, 21 Jan 2003 20:06:35 -0700
Hi all,
Reuters has some ~ priminary news. See:
http://asia.reuters.com/newsArticle.jhtml?type=topNews&storyID=2084917
Meredith
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Subject: Re: Colorado School of Mines Seismometer Competition
From: meredithlamb meredithlamb@.............
Date: Thu, 23 Jan 2003 21:52:32 -0700
Hi John and all,
Thanks John for doing ALOT of work with posting the entrys on
your web site! I find them very interesting to explore, and I'am
looking forward to seeing any remaining papers eventually.
The diamagnetic one was of particular interest too me of course.
They used "end magnets" which seems to double the period of
the levitated spectrographic rod of a similar arrangement here
I copyed (but without end magnets and using curved filed iron
spacers). Chris Chapman has made earlier similar comments
on this in the past also. I've tried using other size magnets where
I put the "end magnets" across the row/s tops ends, and it also has a
similar effect. Most interesting; as it eliminates having to hand
file the iron spacers center region with a man made curvature; which
makes it alot easier to setup and seems to present a consistent
seismo period, for ~ possible easy replication by others.
Take care, Meredith
John & Jan Lahr wrote:
> During the Fall of 2002 the freshmen at the Colorado School of Mines worked on
> designing of an inexpensive seismic system. The details are given here:
>
> http://www.jjlahr.com/science/psn/epics/
>
> In December the best designs were selected and some of the students'
> reports are
> posted here:
> http://www.jjlahr.com/science/psn/epics/reports/
>
> I will continue to add reports as I receive them.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: EMON PROBLEM
From: RADIOTEL@.......
Date: Sat, 25 Jan 2003 21:36:21 EST
NEED HELP WITH EMON. I am using Emon with w CIO Das-8 A/D card. It works
great until I press the F8 key on the computer to view the file. The the
screen reflects :
Loading QUAKEVU.INI file...
Error 7 at line 0 , press any key
Can anyone tell me how to fix this problem. Sure would appreciate the
assistance.
NEED HELP WITH EMON. I am using Emon with w CIO Das-8 A/D card. It works great until I press the F8 key on the computer to view the file. The the screen reflects :
Loading QUAKEVU.INI file...
Error 7 at line 0 , press any key
Can anyone tell me how to fix this problem. Sure would appreciate the assistance.
Subject: New WinQuake Beta Release
From: "Larry Cochrane" cochrane@..............
Date: Sun, 26 Jan 2003 03:19:51 -0800
Hi Everyone,
I've released a new beta version of WinQuake, see this page for a download
link and release notes:
http://www.seismicnet.com/wqdocs/wqbeta.html
Here's what's new in this release. For a complete list of new features and
how to use them please see the release notes.
Both WinQuake and WinSDR (the current beta version just released) now
support a new data structure in the PSN Type 4 event file record. The new
structure contains additional information about the sensor channel. The new
data fields are: Sensor output voltage in volts per cm of movement,
amplifier gain between the sensor and the A/D converter and the peak A/D
input volts. This information and the number of A/D bits make up the Sensor
Sensitivity field in the main fix header section. See this page for more
information on the PSN Type 4 event file format:
http://www.seismicnet.com/psnformat4.html
WinQuake now calculates Mb or Body Wave magnitude. The program uses this
formulate to calculate Mb:
mb = log10(A/T) + 0.01*D + 5.9 A = Peak P wave displacement amplitude in
micrometers, T = Period of the displacement amplitude and D = Distance in
degrees. The program can also calculate the Ms or Mb peak wave period used
by the Ms and Mb formulas.
In the Time Domain Filter dialog box the user can now enter the period in
seconds rather then the frequency. To do this add an 's' after the number.
Example: Entering "20s" will produce a frequency of 0.05 Hz.
The user can now crop an event file. To do this zoom into the area of
interest and then use the View / Crop menu items.
The user can now search for event files on their system. The search includes
filters like min/max magnitude, event to station distance, start and end
times, as well as other filters. To make the search faster, the program can
create a database file. This file contains information about each event file
in a directory and any subdirectories. The database file can be used for the
search rather then opening each file on your system. This drastically
improves the search time if you have a lot of event files.
WinQuake now as a Magnitude Calculator dialog box. See the release notes for
all of the info on this new dialog box.
The Y-Scaling has been changed. The Y-Scale number now represents the peak
data to display. Example: If WinQuake is displaying A/D counts and the
Y-Scale number is set to 1000, WinQuake will display 0 to +-1000 counts. The
program can display the following Y-Scale units: A/D Counts, this is the
default if the Sensor Sensitivity number and A/D Input Volts fields of the
header are 0, Sensor Units (cm, mm etc) if the Sensor Sensitivity is known,
amplifier input voltage, this is the voltage from the sensor element, if the
amp gain and A/D input voltage is known, and A/D volts if this information
is available in the header.
The map window's title now displays the Y-Scale in the title bar of the map
window. This is the distance in km displayed between the top and bottom of
the window.
That's it for the new features. I'm currently working on a major rewrite of
the program so that more then one event file can be displayed in the same
event window. The ability to add new event files to the same window will be
limited to Z, N-S and E-W channels with the same start / end times and
sample rate. This way the data from a two or three component sensor can be
displayed and analyzed in one window. I also will be adding the ability to
read and write a PSN volume set that can contain two or three event files.
Once I have this working and released, I will modify WinSDR so it can
support a two or three channel volume set file that can be read in with
WinQuake.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
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Subject: Re: New WinQuake Beta Release
From: John & Jan Lahr johnjan@........
Date: Sun, 26 Jan 2003 08:44:31 -0700
Hi Larry,
Sounds like a lot of helpful new features for WinQuake.
In your magnitude calculations, do you account for the variation
in overall gain between ~1s P waves for mb and ~ 20 s surface
waves for MS? To a first approximation if the gain of the system
were know at these two frequencies, that would be enough for
rough magnitude determinations.
AmaSeis does not write the new PSN Type 4 format now.
What would be the advantages of making this change? Can
the old format be converted to Type 4 and then the file augmented
with additional data, or does the change need to be made
in AmaSeis?
Cheers,
John Lahr
At 04:19 AM 1/26/2003, you wrote:
>I've released a new beta version of WinQuake, see this page for a download
>link and release notes:
__________________________________________________________
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Subject: RE: EMON PROBLEM
From: steve hammond shammon1@.............
Date: Sun, 26 Jan 2003 10:07:22 -0800
Quakevu is the display program that Ted Black created. It is a stand alone
dos program QUAKEVU.EXE. I'll send you a copy of it if you don't have it. I
use EMON for data capture and Larry's Winquake for viewing the data.
Regards, Steve Hammond PSN San Jose, Aptos CA
-----Original Message-----
From: RADIOTEL@....... [SMTP:RADIOTEL@........
Sent: Saturday, January 25, 2003 6:36 PM
To: psn-l@..............
Subject: Re: EMON PROBLEM
NEED HELP WITH EMON. I am using Emon with w CIO Das-8 A/D card. It works
great until I press the F8 key on the computer to view the file. The the
screen reflects :
Loading QUAKEVU.INI file...
Error 7 at line 0 , press any key
Can anyone tell me how to fix this problem. Sure would appreciate the
assistance.
<< File: ATT00004.html >>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Other thoughts on an inverted pendulum
From: John & Jan Lahr johnjan@........
Date: Sun, 26 Jan 2003 11:19:12 -0700
Hi Ed,
The way to think about the inverted pendulum is that we are balancing two
forces.
Gravity wants to tip the pendulum over, and the greater the angle the
greater this
force is. The spring at the base wants to keep the pendulum
upright, and the
greater the angle the greater the force of the spring is in this
direction.
If I have the math correct, then the problem I had with instability may
have
been due to my setup. My inverted pendulum was made from mounting
a
thin metal rod vertically and putting a mass at the top. The entire
rod bent.
When I tried to achieve a long period, the rod would bend to one side and
stay there!
The spring restoring force is:
Fs = k theta, where k is the spring constant.
The net restoring force is then:
Fnet = Fs - Fg = k theta - mg sin(theta)
The effective spring constant would be:
d (Fnet) / d theta = k - mg cos(theta)
For very small theta, cos(theta) approaches 1.0, so
Effective spring constant = k - mg
It then increases with amplitude.
If I've not made a mistake, this means that the system
will be stable as long as k is greater than mg and that
a very long period small motion natural period can be
obtained if k is just slightly larger than mg.
Damping is another thing that will need to be worked out. When the
pendulum
is properly damped, if it is displaced, for example 1 mm to one side and
released,
it will move through the center position and continue for about 1/20 mm,
turn around,
move through the center and continue for 1/400 mm, etc. In other
words, the
amplitude will die out very quickly.
My suggestion would be to first work on getting as long a period as
possible and then
work on the damping.
Cheers,
John
At 07:40 AM 1/26/2003, you wrote:
John,
some other thoughts......I am attaching a drawing......I hope you receive
it. I will describe it to you anyway.......
I am thinking of possibly extending the brass
rod down into the spring while it still protrudes from the top. I would
also attach a very small level at the bottom of the brass rod to insure
leveling and possibly increase damping. Instead of placing four wooden
dowels (as shown in the drawing) around the spring to possibly prevent
the magnet/weight from getting to the point where it falls/hangs over the
spring I would replace them with a transparent (to view the level)
glass/plastic circular column that reached the elevation of the magnet.
Please remember one thing....I don't know what I'm talking
about.....Ed.
Subject: Re: New WinQuake Beta Release
From: "Larry Cochrane" cochrane@..............
Date: Sun, 26 Jan 2003 13:17:04 -0800
Hi John,
----- Original Message -----
From: "John & Jan Lahr"
To:
Sent: Sunday, January 26, 2003 7:44 AM
Subject: Re: New WinQuake Beta Release
> Hi Larry,
>
> Sounds like a lot of helpful new features for WinQuake.
>
> In your magnitude calculations, do you account for the variation
> in overall gain between ~1s P waves for mb and ~ 20 s surface
> waves for MS? To a first approximation if the gain of the system
> were know at these two frequencies, that would be enough for
> rough magnitude determinations.
WinQuake uses 1 second and 20 seconds for the default P and S waves periods.
The user can determent the approximate period by zooming into either the P
or S wave peak point and then calculating the period. What WinQuake does is
look for the peak amplitude point in the window view (not the whole event
file), it then looks for the two zero crossing points on either side of the
peak wave and calculates the period using the number of samples between the
zero crossing points and the sample rate. Since WinQuake only looks for the
zero crossing point of 1/2 of the wave, it multiplies the period number by 2
to come up with the actual period number.
>
> AmaSeis does not write the new PSN Type 4 format now.
> What would be the advantages of making this change? Can
> the old format be converted to Type 4 and then the file augmented
> with additional data, or does the change need to be made
> in AmaSeis?
AmaSeis would need to be modified to support the PSN Type 4 format. That's
the only way to easily supply all of the new data types to WinQuake. The
other way would be to come up with a conversion program. The additional data
items could be saved in a file keyed off of the station/sensor ID. The
conversion program would use what it can from the AmaSeis event file and
then look up the sensor in the data file for the additional information.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: EMON PROBLEM
From: steve hammond shammon1@.............
Date: Sun, 26 Jan 2003 13:51:51 -0800
For anybody still using EMON. I have QuakeVU and EL (EMON List event files)
programs created by Ted Blank and will be happy to share them via email.
Regards, Steve Hammond PSN San Jose, Aptos CA
-----Original Message-----
From: RADIOTEL@....... [SMTP:RADIOTEL@........
Sent: Saturday, January 25, 2003 6:36 PM
To: psn-l@..............
Subject: Re: EMON PROBLEM
NEED HELP WITH EMON. I am using Emon with w CIO Das-8 A/D card. It works
great until I press the F8 key on the computer to view the file. The the
screen reflects :
Loading QUAKEVU.INI file...
Error 7 at line 0 , press any key
Can anyone tell me how to fix this problem. Sure would appreciate the
assistance.
<< File: ATT00004.html >>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake Beta Release
From: John & Jan Lahr johnjan@........
Date: Sun, 26 Jan 2003 14:53:44 -0700
At 02:17 PM 1/26/2003, you wrote:
>WinQuake uses 1 second and 20 seconds for the default P and S waves periods.
Hi Larry,
Thanks for the added info. I guess the other thing one can do with AmaSeis is
save the file in .sac format. If it is then read by WinQuake, can it be
saved in
Type 4 format?
On the magnitudes, do you allow for just one gain for the system? That would
only work for very broad band systems. Most would need to use a different gain
for 1 s and 20 s periods.
Cheers,
John
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Winquake beta 2.9x
From: "Larry Cochrane" cochrane@..............
Date: Sun, 26 Jan 2003 14:37:33 -0800
Hi Bob,
When you entered 5400 you must have had the drop box next to the number =
set to kilo counts. 5400 kilo counts =3D 5.4 mega counts. Either enter =
5.4 or set the drop box to Counts.
-Larry
----- Original Message -----=20
From: RLLaney@..........
To: cochrane@.................
Sent: Sunday, January 26, 2003 2:28 PM
Subject: Winquake beta 2.9x
Hi Larry:
I just downloaded the new beta version. I haven't gone through =
everything yet, but I am having trouble with the Y scaling. I want to =
use the default of A/D counts, but I can't seem to get the scale units =
to agree with what I use for the window updates. For example, I opened =
a file whose Y values scale ranged from 0 to 5.4 kc. I wanted to change =
the scale to counts. On the Y scale window I entered 5400 and counts =
expecting the scale to change to counts on a scale from 0 to 5400. The =
Y scale changed to counts, but the Y scale window showed 5.4 and =
Megacounts and the trace of the event completely compressed to the zero =
line. I have tried other combinations with other files and cannot get =
the window to update to new settings in the Y scale window. Am I =
missing something?
Thanks.
Bob Laney
Salem, Oregon
Hi Bob,
When you entered 5400 you must have had =
the drop=20
box next to the number set to kilo counts. 5400 kilo counts =3D 5.4 mega =
counts.=20
Either enter 5.4 or set the drop box to Counts.
I just downloaded the new beta=20
version. I haven't gone through everything yet, but I am having =
trouble=20
with the Y scaling. I want to use the default of A/D counts, but =
I can't=20
seem to get the scale units to agree with what I use for the window=20
updates. For example, I opened a file whose Y values scale =
ranged from 0=20
to 5.4 kc. I wanted to change the scale to counts. On the =
Y scale=20
window I entered 5400 and counts expecting the scale to change to =
counts on a=20
scale from 0 to 5400. The Y scale changed to counts, but the Y =
scale=20
window showed 5.4 and Megacounts and the trace of the event completely =
compressed to the zero line. I have tried other combinations =
with other=20
files and cannot get the window to update to new settings in the Y =
scale=20
window. Am I missing something?
Thanks.
Bob=20
Laney Salem, Oregon
Subject: Re: New WinQuake Beta Release
From: "Larry Cochrane" cochrane@..............
Date: Sun, 26 Jan 2003 15:13:37 -0800
Hi John,
> At 02:17 PM 1/26/2003, you wrote:
> >WinQuake uses 1 second and 20 seconds for the default P and S waves
periods.
>
> Hi Larry,
>
> Thanks for the added info. I guess the other thing one can do with
AmaSeis is
> save the file in .sac format. If it is then read by WinQuake, can it be
> saved in Type 4 format?
Yes, you can read in a SAC file and then save it as a PSN Type 4 file. The
problem is the SAC format does not have all of the fields like the new data
structure I just added to WinQuake and WinSDR. Since the new fields are not
part of the SAC format they can not be transferred to the PSN file from the
datalogger. They would have to be manually entered in WinQuake after loading
the SAC file.
>
> On the magnitudes, do you allow for just one gain for the system? That
would
> only work for very broad band systems. Most would need to use a different
gain
> for 1 s and 20 s periods.
There is only one gain (or what I call sensor sensitivity number) field in
the PSN 4 file. As far as I know, this is also the case for both the PEPP
and SAC formats. I think the proper way of handling this is to include the
frequency response of the sensor as a list of poles and zeros. This way a
program like WinQuake can calculate the actual ground motion based on the
frequency of the P or S wave. As you point out WinQuake assumes the sensor
is broadband and has the same sensitivity at 1 or 20 seconds. Adding a list
of poles and zeros to the PSN format is easy, it's just another variable
data structure. Coming up with the correct list of poles and zeros
describing the sensor channel and then using them in WinQuake is a lot more
difficult...
-Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Other thoughts on an inverted pendulum
From: ChrisAtUpw@.......
Date: Mon, 27 Jan 2003 01:06:56 EST
At 07:40 AM 1/26/2003, you wrote:
> John, some other thoughts......I am attaching a drawing......I hope you
> receive it. I will describe it to you anyway.......
> I am thinking of possibly extending the brass rod down into the spring
> while it still protrudes from the top. I would also attach a very small
> level at the bottom of the brass rod to insure leveling and possibly
> increase damping. Instead of placing four wooden dowels (as shown in the
> drawing) around the spring to possibly prevent the magnet/weight from
> getting to the point where it falls/hangs over the spring I would replace
> them with a transparent (to view the level) glass/plastic circular column
> that reached the elevation of the magnet. Please remember one thing....I
> don't know what I'm talking about.....Ed.
In a message dated 26/01/03, johnjan@........ writes:
> Hi Ed,
>
> The way to think about the inverted pendulum is that we are balancing two
> forces.
> Gravity wants to tip the pendulum over, and the greater the angle the
> greater this
> force is. The spring at the base wants to keep the pendulum upright, and
> the
> greater the angle the greater the force of the spring is in this direction.
>
> If I have the math correct, then the problem I had with instability may have
> been due to my setup. My inverted pendulum was made from mounting a
> thin metal rod vertically and putting a mass at the top. The entire rod
> bent.
> When I tried to achieve a long period, the rod would bend to one side and
> stay there!
>
> The CSM student design has a solid rod with a spring at the base.
> http://jjlahr.com/science/psn/epics/reports/sens/index.html
> I think for that design.....
>
> Damping is another thing that will need to be worked out......
>
> My suggestion would be to first work on getting as long a period as
> possible and then work on the damping.
> Cheers,
> John
>
Hi John, Ed,
I have some serious reservations about the above design. Firstly, with
a brass rod and a magnet weight supported by a coil spring, there is nothing
to prevent the spring / rod system 'twanging' or oscillating, laterally or
vertically. There is no damping at all for such motion. As a general rule in
seismometer construction, if parasitic oscillations can occur and are not
damped, they will give problems.
Secondly, since an equal voltage will be induced in the single coil
for equal motion in any lateral direction, the output signal for a quake will
be 'frequency doubled'. The output sensitivity will also be very low, since
although the field through the coil is high, the total field over the coil is
almost constant for small motions. I suspect that the largest signal would be
due to vertical motions of the well sprung magnet!
This can be corrected if you use four small coils in place of the
single one, with the same vertical axis, but connected in opposing pairs. The
motion will be resolved into two signals. An increase in the flux through one
coil of a pair will be added to a decrease in flux through the other coil.
Since the coil centres are now offset to maybe about half the maximum field,
the change in flux with any lateral movement will be high. Vertical motion
will give opposing voltages in a coil pair which ~cancel out.
I would suggest that you try using a light ~1/8" Al rod (knitting
needle?) with the magnet bob on one end and a single spring wire glued /
swaged into an axial hole bored in the other end. If you have a two bar clamp
on the baseplate, you can vary the length of spring wire used. This should be
fairly rigid for vertical movements. The rod can be threaded through a disk
of 1/4" Al plate with a 1/4" hole in the centre, to provide damping. This
seems to give adequate damping with >1/8" separation. You centre the rod in
the hole and move the plate vertically closer to the magnet to increase the
damping. This hole would also control the maximum allowed lateral movement.
The overall stability could be finely adjusted by mounting a second
axial magnet above the bob magnet and positioning it vertically. This could
either increase or decrease the centralising force, depending on whether the
two magnets attract or repel. You will need to adjust the final damping after
setting the period.
However, I would expect the period to be limited by variations in the
spring constant and the magnetic fields with temperature. If you used a
stiffer spring and repelling fields, you might be able to partially
compensate the decrease in stiffness of the spring with the decrease in the
magnetic fields. Precision levelling / balancing the device will be critical.
You won't need a spirit level - the rod will do that for you. HAVE FUN!
Regards,
Chris Chapman
At 07:40 AM 1/26/2003, you wrote:
John, some other thoughts......I am attaching a drawing......I hope you receive it. I will describe it to you anyway.......
I am thinking of possibly extending the brass rod down into the spring while it still protrudes from the top. I would also attach a very small level at the bottom of the brass rod to insure leveling and possibly increase damping. Instead of placing four wooden dowels (as shown in the drawing) around the spring to possibly prevent the magnet/weight from getting to the point where it falls/hangs over the spring I would replace them with a transparent (to view the level) glass/plastic circular column that reached the elevation of the magnet. Please remember one thing....I don't know what I'm talking about.....Ed.
In a message dated 26/01/03, johnjan@........ writes:
Hi Ed,
The way to think about the inverted pendulum is that we are balancing two forces.
Gravity wants to tip the pendulum over, and the greater the angle the greater this
force is. The spring at the base wants to keep the pendulum upright, and the
greater the angle the greater the force of the spring is in this direction.
If I have the math correct, then the problem I had with instability may have
been due to my setup. My inverted pendulum was made from mounting a
thin metal rod vertically and putting a mass at the top. The entire rod bent.
When I tried to achieve a long period, the rod would bend to one side and
stay there!
Damping is another thing that will need to be worked out......
My suggestion would be to first work on getting as long a period as possible and then work on the damping.
Cheers,
John
Hi John, Ed,
I have some serious reservations about the above design. Firstly, with a brass rod and a magnet weight supported by a coil spring, there is nothing to prevent the spring / rod system 'twanging' or oscillating, laterally or vertically. There is no damping at all for such motion. As a general rule in seismometer construction, if parasitic oscillations can occur and are not damped, they will give problems.
Secondly, since an equal voltage will be induced in the single coil for equal motion in any lateral direction, the output signal for a quake will be 'frequency doubled'. The output sensitivity will also be very low, since although the field through the coil is high, the total field over the coil is almost constant for small motions. I suspect that the largest signal would be due to vertical motions of the well sprung magnet!
This can be corrected if you use four small coils in place of the single one, with the same vertical axis, but connected in opposing pairs. The motion will be resolved into two signals. An increase in the flux through one coil of a pair will be added to a decrease in flux through the other coil. Since the coil centres are now offset to maybe about half the maximum field, the change in flux with any lateral movement will be high. Vertical motion will give opposing voltages in a coil pair which ~cancel out.
I would suggest that you try using a light ~1/8" Al rod (knitting needle?) with the magnet bob on one end and a single spring wire glued / swaged into an axial hole bored in the other end. If you have a two bar clamp on the baseplate, you can vary the length of spring wire used. This should be fairly rigid for vertical movements. The rod can be threaded through a disk of 1/4" Al plate with a 1/4" hole in the centre, to provide damping. This seems to give adequate damping with >1/8" separation. You centre the rod in the hole and move the plate vertically closer to the magnet to increase the damping. This hole would also control the maximum allowed lateral movement.
The overall stability could be finely adjusted by mounting a second axial magnet above the bob magnet and positioning it vertically. This could either increase or decrease the centralising force, depending on whether the two magnets attract or repel. You will need to adjust the final damping after setting the period.
However, I would expect the period to be limited by variations in the spring constant and the magnetic fields with temperature. If you used a stiffer spring and repelling fields, you might be able to partially compensate the decrease in stiffness of the spring with the decrease in the magnetic fields. Precision levelling / balancing the device will be critical. You won't need a spirit level - the rod will do that for you. HAVE FUN!
Regards,
Chris Chapman
Subject: Re: Other thoughts on an inverted pendulum
From: "George Harris" gjharris@.............
Date: Mon, 27 Jan 2003 22:59:06 -0800
Some comments on inverted pendulums based on experiments some years ago.
1. I believe that the inverted pendulum becomes unstable for anything =
but very=20
small displacements. It is very difficut to get long periods. It is =
important to
limit the maximum displacement so that the spring (or springs) do not =
take s
permanent set. =20
2. The most usefull configuration found was a mass supported on two flat =
springs.
The base support and the mass were the same width and flat springs =
clamped
to both sides. Adjusting the unsupported spring length provides the =
major=20
adjustment of period, and adding weight is the final adjustment.
3. I had planned to make the structure into a feedback unit. The two =
springs
can be used to provide the conductors to a flat coil on the top of the =
mass.
Two flat magnets on the top can them be used for both feedback and =
damping.
4. It is my belief that a feed back unit can be used in the slightly =
unstable mode. =20
It depends on having the amplifier response designed for good stability.
George Harris
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Cc: Ed Ianni ; johnjan@...........
Sent: Sunday, January 26, 2003 10:06 PM
Subject: Re: Other thoughts on an inverted pendulum
At 07:40 AM 1/26/2003, you wrote:=20
John, some other thoughts......I am attaching a drawing......I hope =
you receive it. I will describe it to you anyway.......=20
I am thinking of possibly extending the brass rod down into the =
spring while it still protrudes from the top. I would also attach a very =
small level at the bottom of the brass rod to insure leveling and =
possibly increase damping. Instead of placing four wooden dowels (as =
shown in the drawing) around the spring to possibly prevent the =
magnet/weight from getting to the point where it falls/hangs over the =
spring I would replace them with a transparent (to view the level) =
glass/plastic circular column that reached the elevation of the magnet. =
Please remember one thing....I don't know what I'm talking about.....Ed.
In a message dated 26/01/03, johnjan@........ writes:=20
Hi Ed,=20
The way to think about the inverted pendulum is that we are =
balancing two forces.=20
Gravity wants to tip the pendulum over, and the greater the angle =
the greater this=20
force is. The spring at the base wants to keep the pendulum =
upright, and the=20
greater the angle the greater the force of the spring is in this =
direction.=20
If I have the math correct, then the problem I had with instability =
may have=20
been due to my setup. My inverted pendulum was made from mounting a =
thin metal rod vertically and putting a mass at the top. The entire =
rod bent.=20
When I tried to achieve a long period, the rod would bend to one =
side and=20
stay there!=20
The CSM student design has a solid rod with a spring at the base.=20
http://jjlahr.com/science/psn/epics/reports/sens/index.html=20
I think for that design.....=20
Damping is another thing that will need to be worked out......=20
My suggestion would be to first work on getting as long a period as =
possible and then work on the damping.=20
Cheers,=20
John=20
Hi John, Ed,=20
I have some serious reservations about the above design. =
Firstly, with a brass rod and a magnet weight supported by a coil =
spring, there is nothing to prevent the spring / rod system 'twanging' =
or oscillating, laterally or vertically. There is no damping at all for =
such motion. As a general rule in seismometer construction, if parasitic =
oscillations can occur and are not damped, they will give problems.=20
Secondly, since an equal voltage will be induced in the single =
coil for equal motion in any lateral direction, the output signal for a =
quake will be 'frequency doubled'. The output sensitivity will also be =
very low, since although the field through the coil is high, the total =
field over the coil is almost constant for small motions. I suspect that =
the largest signal would be due to vertical motions of the well sprung =
magnet!=20
This can be corrected if you use four small coils in place of =
the single one, with the same vertical axis, but connected in opposing =
pairs. The motion will be resolved into two signals. An increase in the =
flux through one coil of a pair will be added to a decrease in flux =
through the other coil. Since the coil centres are now offset to maybe =
about half the maximum field, the change in flux with any lateral =
movement will be high. Vertical motion will give opposing voltages in a =
coil pair which ~cancel out.=20
I would suggest that you try using a light ~1/8" Al rod =
(knitting needle?) with the magnet bob on one end and a single spring =
wire glued / swaged into an axial hole bored in the other end. If you =
have a two bar clamp on the baseplate, you can vary the length of spring =
wire used. This should be fairly rigid for vertical movements. The rod =
can be threaded through a disk of 1/4" Al plate with a 1/4" hole in the =
centre, to provide damping. This seems to give adequate damping with =
>1/8" separation. You centre the rod in the hole and move the plate =
vertically closer to the magnet to increase the damping. This hole would =
also control the maximum allowed lateral movement.=20
The overall stability could be finely adjusted by mounting a =
second axial magnet above the bob magnet and positioning it vertically. =
This could either increase or decrease the centralising force, depending =
on whether the two magnets attract or repel. You will need to adjust the =
final damping after setting the period.=20
However, I would expect the period to be limited by variations =
in the spring constant and the magnetic fields with temperature. If you =
used a stiffer spring and repelling fields, you might be able to =
partially compensate the decrease in stiffness of the spring with the =
decrease in the magnetic fields. Precision levelling / balancing the =
device will be critical. You won't need a spirit level - the rod will do =
that for you. HAVE FUN!=20
Regards,=20
Chris Chapman=20
Some comments on inverted =
pendulums based on=20
experiments some years ago.
1. I believe that the inverted pendulum =
becomes=20
unstable for anything but very
small displacements. It is very =
difficut to=20
get long periods. It is important to
limit the maximum displacement so that =
the spring=20
(or springs) do not take s
permanent set.
2. The most usefull configuration =
found was a=20
mass supported on two flat springs.
The base support and the mass were the =
same width=20
and flat springs clamped
to both sides. Adjusting the =
unsupported spring=20
length provides the major
adjustment of period, and adding weight =
is the=20
final adjustment.
3. I had planned to make the structure =
into a=20
feedback unit. The two springs
can be used to provide the conductors =
to a flat=20
coil on the top of the mass.
Two flat magnets on the top can them be =
used for=20
both feedback and damping.
4. It is my belief that a feed back =
unit can=20
be used in the slightly unstable =
mode. =20
It depends on having the amplifier =
response=20
designed for good stability.
Subject: Re: Other thoughts on =
an=20
inverted pendulum
At 07:40 AM =
1/26/2003,=20
you wrote: John, some other thoughts......I am attaching a =
drawing......I=20
hope you receive it. I will describe it to you =
anyway....... =
I am thinking of=20
possibly extending the brass rod down into the spring while it still =
protrudes from the top. I would also attach a very small level at =
the bottom=20
of the brass rod to insure leveling and possibly increase damping. =
Instead=20
of placing four wooden dowels (as shown in the drawing) around the =
spring to=20
possibly prevent the magnet/weight from getting to the point where =
it=20
falls/hangs over the spring I would replace them with a transparent =
(to view=20
the level) glass/plastic circular column that reached the elevation =
of the=20
magnet. Please remember one thing....I don't know what I'm talking=20
about.....Ed.
In a message =
dated 26/01/03,=20
johnjan@........ writes: Hi Ed,
The way to think about the inverted =
pendulum is=20
that we are balancing two forces. Gravity wants to tip the =
pendulum=20
over, and the greater the angle the greater this force is. =
The=20
spring at the base wants to keep the pendulum upright, and the =
greater=20
the angle the greater the force of the spring is in this direction.=20
If I have the math correct, then the problem I had with =
instability=20
may have been due to my setup. My inverted pendulum was =
made from=20
mounting a thin metal rod vertically and putting a mass at the =
top.=20
The entire rod bent. When I tried to achieve a long =
period, the=20
rod would bend to one side and stay there!
The CSM =
student=20
design has a solid rod with a spring at the base. http=
://jjlahr.com/science/psn/epics/reports/sens/index.html=20
I think for that design.....
Damping is another thing =
that will=20
need to be worked out......
My suggestion would be to first =
work on=20
getting as long a period as possible and then work on the damping.=20
Cheers, John
Hi John, Ed,=20
I have some serious =
reservations=20
about the above design. Firstly, with a brass rod and a magnet weight=20
supported by a coil spring, there is nothing to prevent the spring / =
rod=20
system 'twanging' or oscillating, laterally or vertically. There is no =
damping=20
at all for such motion. As a general rule in seismometer construction, =
if=20
parasitic oscillations can occur and are not damped, they will give =
problems.=20
Secondly, since an equal =
voltage will=20
be induced in the single coil for equal motion in any lateral =
direction, the=20
output signal for a quake will be 'frequency doubled'. The output =
sensitivity=20
will also be very low, since although the field through =
the coil=20
is high, the total field over the coil is almost constant for small =
motions. I=20
suspect that the largest signal would be due to vertical =
motions=20
of the well sprung magnet! =
This can be=20
corrected if you use four small coils in place of the single one, with =
the=20
same vertical axis, but connected in opposing pairs. The motion will =
be=20
resolved into two signals. An increase in the flux through one coil of =
a pair=20
will be added to a decrease in flux through the other coil. Since the =
coil=20
centres are now offset to maybe about half the maximum field, the =
change in=20
flux with any lateral movement will be high. Vertical motion will give =
opposing voltages in a coil pair which ~cancel out.=20
I would suggest that you try =
using a=20
light ~1/8" Al rod (knitting needle?) with the magnet bob on one end =
and a=20
single spring wire glued / swaged into an axial hole bored in the =
other end.=20
If you have a two bar clamp on the baseplate, you can vary the length =
of=20
spring wire used. This should be fairly rigid for vertical movements. =
The rod=20
can be threaded through a disk of 1/4" Al plate with a 1/4" hole in =
the=20
centre, to provide damping. This seems to give adequate damping with =
>1/8"=20
separation. You centre the rod in the hole and move the plate =
vertically=20
closer to the magnet to increase the damping. This hole would also =
control the=20
maximum allowed lateral movement. =
The=20
overall stability could be finely adjusted by mounting a second axial =
magnet=20
above the bob magnet and positioning it vertically. This could either =
increase=20
or decrease the centralising force, depending on whether the two =
magnets=20
attract or repel. You will need to adjust the final damping =
after=20
setting the period. =
However, I=20
would expect the period to be limited by variations in the spring =
constant and=20
the magnetic fields with temperature. If you used a stiffer spring and =
repelling fields, you might be able to partially compensate the =
decrease in=20
stiffness of the spring with the decrease in the magnetic fields. =
Precision=20
levelling / balancing the device will be critical. You won't need a =
spirit=20
level - the rod will do that for you. HAVE FUN!=20
Regards,=20
Chris Chapman=20
Subject: WinQuake Y-Scale Problem
From: "Larry Cochrane" cochrane@..............
Date: Tue, 28 Jan 2003 22:15:18 -0800
Hi Everyone,
It turns out that there is a problem with the Y-Scale dialog box and
displaying A/D counts. I've fixed the problem and release a new beta version
2.9.1b. You can download the new version from this web page:
http://www.seismicnet.com/wqdocs/wqbeta.html
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: WinQuake beta release emails
From: "Larry Cochrane" cochrane@..............
Date: Thu, 30 Jan 2003 22:33:12 -0800
Hi Everyone,
I received two emails regarding the new WinQuake beta release. What I would
like to do is have people use this list to report problems and make
suggestions.
First from Tony in Hawaii...
> Hi again Larry.
> How you doing. I dont mean to ruin your day but..
> Im still having trouble with the Y scale dialog box
> on the 2.9.1b version.
> It is still defaulting to kilocounts and now, stays in kc
> when trying to change to counts.
What you need to do is press the Update button after changing the display
mode to counts. The Y-Scale dialog box should then work correctly. The next
release will fix this problem.
>Also, all the buttons
> are greyed cept for the counts button, which they were on
> the previous version also.
They are grayed out because you do not have the additional information
needed to display volts and sensor units (cm, mm etc of motion). This
information is kept in the header section of the event file. The Sensitivity
number must be entered to enable sensor units. To enable volts and amplifier
input volts display you need to use the new version of WinSDR or manually
enter the data in WinQuake.
>And when I hit the help button
> in the dialog box, WQ locks up.
I have not changed anything around the help system. When you press the help
button in the Y-Scale dialog box it should open the old Y-Scale help page.
Do the other Help buttons work correctly? Anyone else having this problem?
This is why I want to use the PSN-L list rather then personal emails....
> The rest of WQ seems to be working great, altho I still
> havent checked out the new "zoom" function. Could you tell
> me what its for and how to work it?
> Hope its an easy fix. Thanks again for the help.
What new zoom function? I think all of the new features are documented on
the beta release web page. Let me know if I missed something.
Now a email from Larry Conklin....
> Hi Larry,
>
> I've been fooling around a little with the latest Winquake update. Didn't
> find the bug you fixed in the Y-scaling. As far as I can tell, it was
> working fine before you fixed it.
There was a problem when you switched to the Counts display mode. There is
still a problem with the need to hit the Update button when changing to a
new display mode. This hopefully will be fixed in the next release.
> There is one enhancement I'd like to see
> in the y-scaling however. It would be nice if you could lock the scale
> factor (ie. save the current scaling as the default for use when a new
file
> is opened). I typically review a group of files every morning. It would
be
> very helpful to have the same default y-scale locked in, regardless of the
> max/min values contained in the file. It would make file comparisons
> easier, and would save the (admittedly trivial) effort to "turn down the
> gain" as each file is opened as I find myself doing now.
How about if I add a "All Windows" check box similar to the one in the
X-Scale dialog box?
>
> I experimented a little with the search capability and ran into something
> you may or not consider a small bug. I wanted to search based only on a
> date range, so I blanked out the values entered for magnitude, etc. The
> program warned me to enter a number, but being stubborn, is just said ok,
> but didn't supply values for the "don't care" fields. I was rewarded with
a
> crash. Apparently, if you don't want to filter on something like
magnitude,
> you have to supply a range wide enough to guarantee catching everything,
> rather than blanking the fields?
That's correct, just enter a wide range. I'll fix this in the next release.
>
> Finally, when you do the update to allow more than one sensor to be
> displayed in the same window, I hope we don't loose the feature that we
now
> have,whereby opening a second file by invoking the program with the file
> name as a command line parameter results in a new window in the already
open
> instance of the program. I have an Excel spreadsheet that I use as sort
of
> an index into my event files. I have it set up so that I can select a
file
> and send it to Winquake. I was surprised and delighted when I discovered
> that opening a second file from the spreadsheet opened a new data window
vs.
> starting a second instance of the program.
>
I won't change how this works.
Again, if you have any problems, questions, comments etc please use the
PSN-L list. If we use WinQuake in the subject line others who are not
interested can delete the email message.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: WinQuake
From: peaches@............ (Donna Whitaker)
Date: Thu, 30 Jan 2003 22:09:01 -1000 (HST)
Hi Larry.
The Y scale dialog box is working in counts up to 999, then it
reverts to the kilo-counts scale. Is that what it is supposed
to do? I guess I expected to to see 4 and 5 digits on the Y
scale over 999.
Also, about the new "zoom" function, I meant to say "crop".
Sorry about that. The new crop function is working fine.
However, WQ is still locking up when I hit ANY help button.
Ctrl+Alt+Delete shows WQ as not responding. Could it be a problem
with the/my help file?
On a different subject, I have been meaning to tell you, Larry,
that on the WQ Big Island map, the little black dot which
locates the town of Kailua-Kona is not placed in the correct
location. The map is showing it about 8 km North of my station.
Kailua-Kona is actually south of my station by about
10 km. Its no big deal. I've just been meaning to bring it to
your attention for quite awhile.
Thanks again for your help Larry.
Aloha
Tony Potenzo
Hawaii PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinQuake beta release emails
From: "Larry Conklin" lconklin@............
Date: Fri, 31 Jan 2003 16:36:40 -0500
Hi again,
The incentive behind my "lock default y-scale" suggestion was that when I do
my daily file review, most of the files are just background noise. When the
file
opens, the automatic scaling based on the max/min data values boosts
the"gain"
too high to make sense of the data. If you could set a default initial
scaling, you
could set it so these no-event files would open at an appropriate scaling
for the
typical system background noise. The check box would be "use current
scaling
as the default." An "all windows" option would be handy as well. (What the
heck,
it's just a simple matter of programming", right?)
Larry Conklin
> > There is one enhancement I'd like to see
> > in the y-scaling however. It would be nice if you could lock the scale
> > factor (ie. save the current scaling as the default for use when a new
> file
> > is opened). I typically review a group of files every morning. It
would
> be
> > very helpful to have the same default y-scale locked in, regardless of
the
> > max/min values contained in the file. It would make file comparisons
> > easier, and would save the (admittedly trivial) effort to "turn down the
> > gain" as each file is opened as I find myself doing now.
>
> How about if I add a "All Windows" check box similar to the one in the
> X-Scale dialog box?
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Seismic particle detector?
From: "David Saum" DSaum@............
Date: Fri, 31 Jan 2003 16:38:24 -0500
Wired Magazine online
Issue 11.02 - February 2003
Deep Impact
http://www.wired.com/wired/archive/11.02/matter.html?pg=1&topic=&topic_set=
Enjoy,
Dave Saum
http://www.infiltec.com/seismo/
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Strong Local Quakes
From: "Bobodude" bobodude@.............
Date: Sun, 2 Feb 2003 11:03:54 -0800
FYI
10:22 Calavaras Fault 4.2 mag. My sensor is saturated.
10:52 Calavarus Fault 4.0 mag.
Its 11:00 and my sdr screen is still saturated.
The Oakley Siesmo Station, Oakley Calif.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinQuake beta release emails
From: "Larry Cochrane" cochrane@..............
Date: Sun, 2 Feb 2003 15:51:39 -0800
Larry,
I just got done adding both the "All Windows" and the default open Y-Scale
features. I'll have a new release ready in a few days.
Regards,
Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Larry Conklin"
To:
Sent: Friday, January 31, 2003 1:36 PM
Subject: Re: WinQuake beta release emails
> Hi again,
>
> The incentive behind my "lock default y-scale" suggestion was that when I
do
> my daily file review, most of the files are just background noise. When
the
> file
> opens, the automatic scaling based on the max/min data values boosts
> the"gain"
> too high to make sense of the data. If you could set a default initial
> scaling, you
> could set it so these no-event files would open at an appropriate scaling
> for the
> typical system background noise. The check box would be "use current
> scaling
> as the default." An "all windows" option would be handy as well. (What
the
> heck,
> it's just a simple matter of programming", right?)
>
> Larry Conklin
>
> > > There is one enhancement I'd like to see
> > > in the y-scaling however. It would be nice if you could lock the
scale
> > > factor (ie. save the current scaling as the default for use when a new
> > file
> > > is opened). I typically review a group of files every morning. It
> would
> > be
> > > very helpful to have the same default y-scale locked in, regardless of
> the
> > > max/min values contained in the file. It would make file comparisons
> > > easier, and would save the (admittedly trivial) effort to "turn down
the
> > > gain" as each file is opened as I find myself doing now.
> >
> > How about if I add a "All Windows" check box similar to the one in the
> > X-Scale dialog box?
> >
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinQuake
From: "Larry Cochrane" cochrane@..............
Date: Sun, 2 Feb 2003 16:32:14 -0800
Hi Tony,
> Hi Larry.
>
> The Y scale dialog box is working in counts up to 999, then it
> reverts to the kilo-counts scale. Is that what it is supposed
> to do? I guess I expected to to see 4 and 5 digits on the Y
> scale over 999.
The Y-Scale now goes between 1 and 999.999 and then the multiplier changes.
This way counts is handled the same way as volts and sensor units.
> Also, about the new "zoom" function, I meant to say "crop".
> Sorry about that. The new crop function is working fine.
> However, WQ is still locking up when I hit ANY help button.
> Ctrl+Alt+Delete shows WQ as not responding. Could it be a problem
> with the/my help file?
Make sure you have PSNExplorer in the same directory as WinQuake. You might
try and reinstall WinQuake on the system. Maybe that will correct the help
system problem. Also, make sure you have the current version (5.5 or 6.0) of
Internet Explorer install on your system. PSNExplorer requires that IE be
installed on the system to work correctly.
> On a different subject, I have been meaning to tell you, Larry,
> that on the WQ Big Island map, the little black dot which
> locates the town of Kailua-Kona is not placed in the correct
> location. The map is showing it about 8 km North of my station.
> Kailua-Kona is actually south of my station by about
> 10 km. Its no big deal. I've just been meaning to bring it to
> your attention for quite awhile.
You can correct this yourself. First you will need the correct location of
Kailua-Kona. This should be available on the Internet somewhere. Now edit
the city.dat file with a text editor like Notepad. Locate the city in the
file and change the latitude and longitude to the correct numbers. When
saving the file, make sure you save it as a text file with line-breaks.
Notepad likes to append .txt to the saved file name so you will need to
rename the file back to city.dat. If you send me the correct location of the
city I will update my copy of city.dat file. This way the city location will
show up correctly on the next software release.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Seismometer
From: Ed Ianni eianni2@...........
Date: Sun, 09 Feb 2003 09:37:40 -0500
Hi all;
SS-1 Ranger Seismometer (item 3310387589)........on EBAY.
Ed.
Subject: Things are moving in Gilroy.
From: steve hammond shammon1@.............
Date: Sun, 9 Feb 2003 13:56:24 -0800
3.4, 2.9 3.0 east side ofGilroy CA in the last 1/2 hour.
Regards, Steve Hammond PSN San Jose, CA
http://www.gusd.k12.ca.us/schools/svjh/seismic/
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: BBC news article about infrasound
From: "Charles R. Patton" charles.r.patton@........
Date: Fri, 14 Feb 2003 10:01:23 -0800
FYI, some articles about infrasound.
main article on volcanoes and nuclear blast monitoring:
http://news.bbc.co.uk/2/hi/in_depth/sci_tech/2003/denver_2003/2763657.stm
pictures of a monitoring site and the detector:
http://news.bbc.co.uk/2/hi/science/nature/1522932.stm
a miscellaneous link on infrasound:
http://news.bbc.co.uk/2/hi/science/nature/2309505.stm
All the BBC articles have additonal links to further reading.
Regards,
Charles R. Patton
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: FW: Folded Pendulum Design
From: "Brady Romberg" bromberg@.........
Date: Sat, 15 Feb 2003 20:10:53 -0700
I am currently a freshman at Colorado School of Mines and last semester
for one of my classes I was required to design and build a working
seismometer. Our final design consisted of a folded pendulum which used
magnetic induction, an amplifying filter circuit, an A/D converter, and
Alan Jones' AmaSeis software. I am continuing on with my folded
pendulum design this semester and I am trying to make some improvements
on it but I have some questions that I am having trouble finding the
answer for so if anyone could help me find some answers I would really
appreciate it.
Where could I find a thin flexible metal sheet that I could use for the
inverted pendulum joints?
Where could I find what I believe is called a PZ electro crystal (the
crystal that expands when it receives a current) for testing our unit?
Where could I find information about optimizing the magnet / coil /
damper system?
How would I go about integrating an A/D converter into my circuit that
would have an output of " 98156158 " for the values 98,
156, 158?
How many samples per second does the 8 bit have compared to the 10 bit
and the 12 bit, and what exactly does bit mean?
If you have any questions about my design, advice, or helpful
information you can contact me at bromberg@.........
Thank you for your time.
Brady Romberg
I am currently a freshman at Colorado School of Mines =
and
last semester for one of my classes I was required to design and build a
working seismometer.Our =
final
design consisted of a folded pendulum which used magnetic induction, an
amplifying filter circuit, an A/D converter, and Alan Jones’ =
AmaSeis
software.I am continuing =
on with
my folded pendulum design this semester and I am trying to make some
improvements on it but I have some questions that I am having trouble =
finding
the answer for so if anyone could help me find some answers I would =
really
appreciate it. =
Where could I find a thin flexible metal sheet that I =
could
use for the inverted pendulum joints?
Where could I find what I believe is called a PZ =
electro
crystal (the crystal that expands when it receives a current) for =
testing our
unit?
Where could I find information about optimizing the =
magnet /
coil / damper system?
How would I go about integrating an A/D converter =
into my
circuit that would have an output of “98<cr><lf>156<cr><lf>158
“ for the values 98, 156, 158?
How many samples per second does the 8 bit =
have
compared to the 10 bit and the 12 bit, and what exactly does bit =
mean?
If you have any questions about my design, =
advice,
or helpful information you can contact me at bromberg@.........
Thank you for your =
time.
Brady Romberg
Subject: Re: BBC news article about infrasound
From: Arie Verveer greensky@............
Date: Sun, 16 Feb 2003 11:14:30 +0800
Regarding Infrasound; over the last year I had been experimenting with the
detection of infrasound and found the following. The upper zonal winds play
an important roll in detecting infrasound from a distance source. The sound
is refracted as it goes through the atmosphere and the zonal winds can act as
a reflecting layer. (Typically around 50 km ). These zonal winds change direction
and velocity within the year and thus the detection of infrasound varies. Using the
ocean as a infrasound source you can determine when Zonal winds change direction
( On a season). Also their is Diurnal wind and local wind's. By the way the earth is
a
reflecting layer, so infrasound can bounce between the 50 km region and the earth and
so propagates around the earth. The lower the frequency the further the wave can
propagate.
I used a setup similar to " http://www.belljar.net/microbar.htm " with a front end
amplifier/filter
and different sensor. You can monitor directly to the atmosphere but wind will, and
I mean "will" be a major problem. On "NO" wind days the results are good, but let
face it the
wind blows more often then it doesn't, especially when the sensor is so sensitive. I
then
tried using a acoustic pip array with some success. But my station is located in a
wooded area
and the array size was limited. So I tended to record wind and its turbulence. In the
end I used
6 meters of very flexible thin walled silicon tube as the sensor head. This was
located in a
building with many vents and dust filters. A pressure bleed was located on the other
side of
the detectors diaphragm. Bingo, it worked well to winds unto 10 - 15 km per hour.
So for most of the time I received a good signal. It detected mine blasts some
160 km away. First you got the seismic signal the after some 7 to 10 minutes you got
the
infrasound. Mainly around 9 minutes as the the signal reflected and refracted in the
atmosphere.
I ran this configuration for about a 40 days before the seismic and infrasound
station was
closed down. I do believe you could record infrasound form a local quake if the
winds were
right and the quake intensity was moderate. You do record local infrasound from a
quake
as the seismic signature passes you. Though the signal to noise / ratio is poor. As a
thought,
one could put a weight on the silicon tubing and maybe it could record quakes. I
wonder
what the frequency response would be? Just an idea.
Additionally I have recorded infrasound from meteors and local explosions.
So if anyone is thinking of setting up an infrasound station, let me know and I'll
pass on any info I have.
Cheers
Arie
To stop spam my email is now broken in 2 bits. Join this "greensky" to
"@............"
without the " ".
> "Charles R. Patton" wrote:
> FYI, some articles about infrasound.
>
> main article on volcanoes and nuclear blast monitoring:
> http://news.bbc.co.uk/2/hi/in_depth/sci_tech/2003/denver_2003/2763657.stm
>
> pictures of a monitoring site and the detector:
> http://news.bbc.co.uk/2/hi/science/nature/1522932.stm
>
> a miscellaneous link on infrasound:
> http://news.bbc.co.uk/2/hi/science/nature/2309505.stm
>
> All the BBC articles have additonal links to further reading.
>
> Regards,
> Charles R. Patton
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: BBC news article about infrasound
From: "Steve Hansen" shansen@........
Date: Sun, 16 Feb 2003 03:49:37 -0000
Thanks for the update on what you've been doing with your microbarograph
Arie. The one I described at http://www.belljar.net/microbar.htm has been
substantially modified and, come springtime, will be installed underground
to minimize thermal effects (I got the hole half dug in the fall, then it
started to snow, and snow and snow).
I am interested in your silicone tubing idea. Can you provide some more
details?
Steve Hansen
----- Original Message -----
From: "Arie Verveer"
To:
Sent: Sunday, February 16, 2003 3:14 AM
Subject: Re: BBC news article about infrasound
> In the end I used 6 meters of very flexible thin walled silicon tube as
the sensor head. This was
> located in a building with many vents and dust filters.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: BBC news article about infrasound
From: Arie Verveer greensky@............
Date: Sun, 16 Feb 2003 16:00:00 +0800
Wow, the original author! Hi Steve, Similarly, I had the MKS sensor and
pluming placed in a cooler, but surrounded the detector with lots of freezer
packs to give the device some thermal inertia. Seemed to work within the sensors
time constant. ( very fine needle valve)
From the cooler box to the silicon tubing was about 1.5 meters of stiff hose. The
sensor tubing was 6 meters of "BMDGB0802" ( 7.9 X 12.7 mm) Silicon tube that
was obtained from a medical supply company. Its wall thickness is 2.4 mm. I do
know their is a thinner wall thickness tube but the cost nearly doubled, so the 2.4mm
was the one. This tube was then wound in a tight coil.
It was housed in a special building at work, but if it were, housed in a big
box with ventilation holes + air conditioner filters and baffles then that should
mimic the building.
Cheers
Arie
> Steve Hansen wrote:
> Thanks for the update on what you've been doing with your microbarograph
> Arie. The one I described at http://www.belljar.net/microbar.htm has been
> substantially modified and, come springtime, will be installed underground
> to minimize thermal effects (I got the hole half dug in the fall, then it
> started to snow, and snow and snow).
>
> I am interested in your silicone tubing idea. Can you provide some more
> details?
>
> Steve Hansen
>
> ----- Original Message -----
> From: "Arie Verveer"
> To:
> Sent: Sunday, February 16, 2003 3:14 AM
> Subject: Re: BBC news article about infrasound
>
> > In the end I used 6 meters of very flexible thin walled silicon tube as
> the sensor head. This was
> > located in a building with many vents and dust filters.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Folded Pendulum Design
From: "Jonathan Peakall" jpeakall@............
Date: Sun, 16 Feb 2003 07:44:19 -0800
Brady,
>How would I go about integrating an A/D converter into my circuit that =
would have an output of >" 98156158 " for the values =
98, 156, 158?
You need a microcontroller, such as a Stamp or PIC. This reads the ADC =
and then sends the results and the control characters.
>How many samples per second does the 8 bit have compared to the 10 >bit =
and the 12 bit, and what exactly does bit mean?
Bits have nothing to do with sample rates. The sample rate depends on =
the ADC that you have. The 10 bit 12 bit thing has to do with the =
resolution of the ADC, not the speed. A 10 bit ADC returns (I believe) a =
number between 1 and 2048. A 12 bit returns a number between 1-4096. So =
smaller divisions can be acheived with an ADC with a higher bit rating.
HTH,
Jonathan
www.madlabs.info
----- Original Message -----=20
From: Brady Romberg=20
To: psn-l@.................
Sent: Saturday, February 15, 2003 7:10 PM
Subject: FW: Folded Pendulum Design
I am currently a freshman at Colorado School of Mines and last =
semester for one of my classes I was required to design and build a =
working seismometer. Our final design consisted of a folded pendulum =
which used magnetic induction, an amplifying filter circuit, an A/D =
converter, and Alan Jones' AmaSeis software. I am continuing on with my =
folded pendulum design this semester and I am trying to make some =
improvements on it but I have some questions that I am having trouble =
finding the answer for so if anyone could help me find some answers I =
would really appreciate it. =20
=20
Where could I find a thin flexible metal sheet that I could use for =
the inverted pendulum joints?
Where could I find what I believe is called a PZ electro crystal (the =
crystal that expands when it receives a current) for testing our unit?
Where could I find information about optimizing the magnet / coil / =
damper system?
How would I go about integrating an A/D converter into my circuit that =
would have an output of " 98156158 " for the values 98, =
156, 158?
How many samples per second does the 8 bit have compared to the 10 bit =
and the 12 bit, and what exactly does bit mean?
=20
If you have any questions about my design, advice, or helpful =
information you can contact me at bromberg@............
Thank you for your time.
=20
Brady Romberg
=20
Brady,
>How would I go about =
integrating=20
an A/D converter into my circuit that would have an output of =
>=9398<cr><lf>156<cr><lf>158=20
=93 for the values 98, 156, 158?
You need a =
microcontroller,=20
such as a Stamp or PIC. This reads the ADC and then sends the results =
and the=20
control characters.
>How many =
samples per=20
second does the 8 bit have compared to the 10 >bit and the 12 bit, =
and what=20
exactly does bit mean?
Bits have nothing =
to do with=20
sample rates. The sample rate depends on the ADC that you have. The 10 =
bit 12=20
bit thing has to do with the resolution of the ADC, not the speed. A 10 =
bit ADC=20
returns (I believe) a number between 1 and 2048. A 12 bit returns a =
number=20
between 1-4096. So smaller divisions can be acheived with an ADC with a =
higher=20
bit rating.
I am currently a =
freshman at=20
Colorado School of Mines and last semester for one of my classes I was =
required to design and build a working seismometer. Our final design consisted =
of a folded=20
pendulum which used magnetic induction, an amplifying filter circuit, =
an A/D=20
converter, and Alan Jones=92 AmaSeis software. I am continuing on with my =
folded=20
pendulum design this semester and I am trying to make some =
improvements on it=20
but I have some questions that I am having trouble finding the answer =
for so=20
if anyone could help me find some answers I would really appreciate =
it. =
Where could I find a =
thin flexible=20
metal sheet that I could use for the inverted pendulum=20
joints?
Where could I find what =
I believe=20
is called a PZ electro crystal (the crystal that expands when it =
receives a=20
current) for testing our unit?
Where could I find =
information=20
about optimizing the magnet / coil / damper=20
system?
How would I go about =
integrating=20
an A/D converter into my circuit that would have an output of =9398<cr><lf>156<cr><lf>158=20
=93 for the values 98, 156, 158?
How many samples =
per=20
second does the 8 bit have compared to the 10 bit and the 12 bit, and =
what=20
exactly does bit mean?
If you have any =
questions=20
about my design, advice, or helpful information you can contact me at =
bromberg@.........=20
Thank you for =
your=20
time.
Brady=20
Romberg
Subject: Re: FW: Folded Pendulum Design
From: ChrisAtUpw@.......
Date: Sun, 16 Feb 2003 11:01:13 EST
In a message dated 16/02/03, bromberg@......... writes:
> I am currently a freshman at Colorado School of Mines and last semester fo=
r=20
> one of my classes I was required to design and build a working seismometer=
..=20
> Our final design consisted of a folded pendulum which used magnetic=20
> induction, an amplifying filter circuit, an A/D converter, and Alan Jones=
=E2=80=99=20
> AmaSeis software. I am continuing on with my folded pendulum design this=20
> semester and I am trying to make some improvements on it but I have some=20
> questions that I am having trouble finding the answer for so if anyone=20
> could help me find some answers I would really appreciate it. =20
> =20
> Where could I find a thin flexible metal sheet that I could use for the=20
>=20
Hi Brady,
Look for Model Shops which stock K&S metals http://www.ksmetals.com/=20
They sell 2 thou stainless steel and also 2 thou brass.=20
Alternatively, look for a tool shop or Engineering supplier who stock=
=20
1.5 thou 'shim strip' or 'feeler gauge' strip. It is about 1/2" wide and 12"=
=20
long.=20
For fine steel wire, go to a music shop and ask for mandolin strings.=
=20
These are stocked down to 7 thou. dia. You can get nickel plated strings for=
=20
guitars from 8 thou dia. See http://www.daddario.com/
W
> here could I find what I believe is called a PZ electro crystal (the cryst=
al=20
>=20
Spark igniters for gas appliances / cigarette lighters use them. They=
=20
react to large voltage changes, not to current. Suggest that you do a Web=20
search. I think that I have seen them being sold as PZT crystals.
W
> here could I find information about optimizing the magnet / coil / damper=20
>=20
I can make suggestions when I know something about the design of your=
=20
seismometer, the mass and the likely drift. I suggest using Neodymium magnet=
s=20
in groups of two or four with mild steel backing plates. See=20
www.wondermagnet.com for rectangular / V shaped magnets. These can give a=20
considerable increase in sensitivity and linearity over Alnico U magnets.
H
> ow would I go about integrating an A/D converter into my circuit that woul=
d=20
> have an output of =E2=80=9C 98156158 =E2=80=9C for the va=
lues 98, 156,=20
>=20
The data logging programmes usually have this built in as part of the=20
software. Dataq provide suggested programme modules for their systems.=20
Otherwise, you would have to write a computer programme to do this / us=
e=20
a dedicated processor like a Basic Stamp or a PIC.
H
> ow many samples per second does the 8 bit have compared to the 10 bit and=20
> the 12 bit, and what exactly does bit mean?
You look up the max sample rate from the data sheet for the device. You=20
can download these from Manufacturer's Websites. Then you have the problem o=
f=20
access to the computer. For the $24 Dataq 10 bit A/Ds, you have a maximum of=
=20
240 samples / sec total, but you can opt for less and four channels will giv=
e=20
1/4 this. You choose the number of samples / sec from the max frequency you=20
wish to record. For a frequency of f, the minimum would be 2f sps and a more=
=20
reasonable rate would be 4f or 5f.
Numbers are held in a computer in binary form. Instead of using 0 to 9 i=
n=20
the decimal system for each decade, you use 0 and 1. So 13 decimal =3D 10 +=20=
3;=20
in powers of 2 =3D 8 + 4 + 0 + 1 =3D 1101 in binary. A byte is a term for 8=20=
bits=20
=3D numbers from 0 to 255.
A 10 bit A/D will have 1023 steps for the total range (1024 levels).=20
For a +/-10V input range, the step size will be 4.88 milli V. A 12 bit A/D=20
will have 4095 steps and a 16 bit will have 65535.
> If you have any questions about my design, advice, or helpful information=20
> you can contact me at bromberg@mines=
..edu
It is a bit difficult providing good advice when we do not have a=20
drawing or description of your proposed device. John Lahr has a picture on=20
his Website, but it does not show sufficient detail. Is there an online copy=
=20
of your report anywhere?
Regards,
Chris Chapman
In a message dated 16/02/03, bromberg@......... writes=
:
I am currently a freshman a=
t Colorado School of Mines and last semester for one of my classes I was req=
uired to design and build a working seismometer. Our final design cons=
isted of a folded pendulum which used magnetic induction, an amplifying filt=
er circuit, an A/D converter, and Alan Jones=E2=80=99 AmaSeis software. &nbs=
p;I am continuing on with my folded pendulum design this semester and I am t=
rying to make some improvements on it but I have some questions that I am ha=
ving trouble finding the answer for so if anyone could help me find some ans=
wers I would really appreciate it.
=20
Where could I find a thin flexible metal sheet that I could use for the=20=
inverted pendulum joints?
Hi Brady,
Look for Model Shops which stock K&=
amp;S metals http://www.ksmetals.com/ They sell 2 thou stainless steel and a=
lso 2 thou brass.=20
Alternatively, look for a tool shop=
or Engineering supplier who stock 1.5 thou 'shim strip' or 'feeler gauge' s=
trip. It is about 1/2" wide and 12" long.=20
For fine steel wire, go to a music=20=
shop and ask for mandolin strings. These are stocked down to 7 thou. dia. Yo=
u can get nickel plated strings for guitars from 8 thou dia. See http://www.=
daddario.com/
W
here could I find what I be=
lieve is called a PZ electro crystal (the crystal that expands when it recei=
ves a current) for testing our unit?
Spark igniters for gas appliances /=
cigarette lighters use them. They react to large voltage changes, not to cu=
rrent. Suggest that you do a Web search. I think that I have seen them being=
sold as PZT crystals.
W
here could I find informati=
on about optimizing the magnet / coil / damper system?
I can make suggestions when I know=20=
something about the design of your seismometer, the mass and the likely drif=
t. I suggest using Neodymium magnets in groups of two or four with mild stee=
l backing plates. See www.wondermagnet.com for rectangular / V shaped magnet=
s. These can give a considerable increase in sensitivity and linearity over=20=
Alnico U magnets.
H
ow would I go about integra=
ting an A/D converter into my circuit that would have an output of =E2=80=
=9C
98<cr><lf>156<cr><lf>158=20=
=E2=80=9C for the values 98, 156, 158?
The data logging programmes usually have this built i=
n as part of the software. Dataq provide suggested programme modules for the=
ir systems.=20
Otherwise, you would have to write a computer program=
me to do this / use a dedicated processor like a Basic Stamp or a PIC.
H
ow many samples per second=20=
does the 8 bit have compared to the 10 bit and the 12 bit, and what exactly=20=
does bit mean?
You look up the max sample rate from the data sheet f=
or the device. You can download these from Manufacturer's Websites. Then you=
have the problem of access to the computer. For the $24 Dataq 10 bit A/Ds,=20=
you have a maximum of 240 samples / sec total, but you can opt for less and=20=
four channels will give 1/4 this. You choose the number of samples / sec fro=
m the max frequency you wish to record. For a frequency of f, the minimum wo=
uld be 2f sps and a more reasonable rate would be 4f or 5f.
Numbers are held in a computer in binary form. Instea=
d of using 0 to 9 in the decimal system for each decade, you use 0 and 1. So=
13 decimal =3D 10 + 3; in powers of 2 =3D 8 + 4 + 0 + 1 =3D 1101 in binary.=
A byte is a term for 8 bits =3D numbers from 0 to 255.
A 10 bit A/D will have 1023 steps f=
or the total range (1024 levels). For a +/-10V input range, the step size wi=
ll be 4.88 milli V. A 12 bit A/D will have 4095 steps and a 16 bit will have=
65535.
If you have any=
questions about my design, advice, or helpful information you can contact m=
e at bromberg@.........
It is a bit difficult providing goo=
d advice when we do not have a drawing or description of your proposed devic=
e. John Lahr has a picture on his Website, but it does not show sufficient d=
etail. Is there an online copy of your report anywhere?
Regards,
Chris Chapman
Subject: Re: BBC news article about infrasound
From: "Steve Hansen" shansen@........
Date: Sun, 16 Feb 2003 18:52:51 -0000
Hi Arie,
I got your separate message with the documentation. If my regular PC weren't
in the shop I'd take a picture of what mine evolved into. Basically it's
sort of modelled on Chris Hayward's set up at SMU with the entire
transducer/reservoir/leak assembly in a length of 4" PVC pipe. The
components are at the bottom of the tube and the rest is filled with
insulation. The hole that I started before everything froze over will be
about 4-5 ft. deep.
I've amassed a pile of literature on noise reduction pipes and the like but
it sounds like my site is not dissimilar from yours and not conducive to
running hundreds of feet of soaker hose all around.
Silicone tubing as you describe is readily available in various diameters
and walls from US Plastic www.usplastic.com and one item, 54036, is 3/8" id
x 1/2" od (i.e. somewhat thinner wall than yours) and is priced at $0.82/ft
in 1 ft. increments. What do you see as the advantage of the thinner wall
tube?
Steve
> Wow, the original author! Hi Steve, Similarly, I had the MKS sensor and
> pluming placed in a cooler, but surrounded the detector with lots of
freezer
> packs to give the device some thermal inertia. Seemed to work within the
sensors
> time constant. ( very fine needle valve)
>
> From the cooler box to the silicon tubing was about 1.5 meters of stiff
hose. The
> sensor tubing was 6 meters of "BMDGB0802" ( 7.9 X 12.7 mm) Silicon tube
that
> was obtained from a medical supply company. Its wall thickness is 2.4 mm.
I do
> know their is a thinner wall thickness tube but the cost nearly doubled,
so the 2.4mm
>
> was the one. This tube was then wound in a tight coil.
>
> It was housed in a special building at work, but if it were, housed in a
big
> box with ventilation holes + air conditioner filters and baffles then
that should
> mimic the building.
>
> Cheers
>
> Arie
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: A-D Board for sale: 12-bit with WWV option
From: hammond hammond@...........
Date: Sun, 16 Feb 2003 11:17:29 -0900
I have a 12-bit A-D board with the WWV option for sale on eBay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2509092078
Bob Hammond
Public Seismic Network - Alaska
http://apsn.awcable.com
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: BBC news article about infrasound
From: John Hernlund hernlund@............
Date: Sun, 16 Feb 2003 12:23:07 -0800
This is quite interesting Arie. It reminds me of a talk I saw recently
by a woman who uses the ionosphere as a seismometer of sorts. I figured
some of you might be interested in this. The way it works is as
follows: Small perturbations to the atmosphere just above the ground
due to passing Rayleigh waves (love waves are pure shear, and can't
propagate into a gas) propagate as low frequency sound waves upward
into the atmosphere. Because the atmosphere becomes less dense
approximately exponentially with height, the sound wave velocity
decreases. Just like in the Earth, eg. slowing down of the waves due to
sedimentary basins, etc., causes the waves to increase in amplitude in
inverse proportion to their change in density. So these very slight
sound waves at the surface due to Rayleigh seismic waves can obtain
amplitudes of hundreds of meters in the upper atmosphere where the
normal gas gives way to ions. This causes the ionosphere to oscillate
up and down. This latter effect can be measured by either bouncing
radar waves off the bottom of the ionosphere or using a satellite to
measure the ion density from above. It is quite amazing how well the
seismic records and ionospheric records correlate. She even had some
records indicating that this effect can detect tsunamis as well. This
atmospheric seismometer is by no means broadband, as there are
complicated damping effects in the normal and ionized atmosphere. I was
thinking this could give us a cheap way of measuring seismic surface
waves on other planets, which is desperately needed to constrain the
geophysics that we attempt to extrapolate to bodies with little or no
data. But this is not an easy proposition, as the atmospheres and
magnetic fields shaping the behavior of such things are profoundly
different on each planet.
Regarding the propagation of infra-sound through the atmosphere I
wonder if you have tried to model this as a wave guide? Certainly the
amplitudes are there. I might expect that this type of thing would be
very dispersive, as shorter wavelength energy begins cascading into
longer wavelengths due to the geometric and damping effects in the
upper atmosphere.
Cheers!
John
On Saturday, February 15, 2003, at 07:14 PM, Arie Verveer wrote:
> Regarding Infrasound; over the last year I had been experimenting
> with the
> detection of infrasound and found the following. The upper zonal winds
> play
> an important roll in detecting infrasound from a distance source. The
> sound
> is refracted as it goes through the atmosphere and the zonal winds can
> act as
> a reflecting layer. (Typically around 50 km ). These zonal winds
> change direction
> and velocity within the year and thus the detection of infrasound
> varies. Using the
> ocean as a infrasound source you can determine when Zonal winds change
> direction
> ( On a season). Also their is Diurnal wind and local wind's. By the
> way the earth is
> a
> reflecting layer, so infrasound can bounce between the 50 km region
> and the earth and
>
> so propagates around the earth. The lower the frequency the further
> the wave can
> propagate.
>
> I used a setup similar to " http://www.belljar.net/microbar.htm "
> with a front end
> amplifier/filter
> and different sensor. You can monitor directly to the atmosphere but
> wind will, and
> I mean "will" be a major problem. On "NO" wind days the results are
> good, but let
> face it the
> wind blows more often then it doesn't, especially when the sensor is
> so sensitive. I
> then
> tried using a acoustic pip array with some success. But my station is
> located in a
> wooded area
> and the array size was limited. So I tended to record wind and its
> turbulence. In the
> end I used
> 6 meters of very flexible thin walled silicon tube as the sensor head.
> This was
> located in a
> building with many vents and dust filters. A pressure bleed was
> located on the other
> side of
> the detectors diaphragm. Bingo, it worked well to winds unto 10 - 15
> km per hour.
>
> So for most of the time I received a good signal. It detected mine
> blasts some
> 160 km away. First you got the seismic signal the after some 7 to 10
> minutes you got
> the
> infrasound. Mainly around 9 minutes as the the signal reflected and
> refracted in the
> atmosphere.
> I ran this configuration for about a 40 days before the seismic and
> infrasound
> station was
> closed down. I do believe you could record infrasound form a local
> quake if the
> winds were
> right and the quake intensity was moderate. You do record local
> infrasound from a
> quake
> as the seismic signature passes you. Though the signal to noise /
> ratio is poor. As a
> thought,
> one could put a weight on the silicon tubing and maybe it could record
> quakes. I
> wonder
> what the frequency response would be? Just an idea.
>
> Additionally I have recorded infrasound from meteors and local
> explosions.
>
> So if anyone is thinking of setting up an infrasound station, let me
> know and I'll
> pass on any info I have.
>
> Cheers
>
> Arie
>
> To stop spam my email is now broken in 2 bits. Join this "greensky" to
> "@............"
> without the " ".
>
>
>
>> "Charles R. Patton" wrote:
>
>> FYI, some articles about infrasound.
>>
>> main article on volcanoes and nuclear blast monitoring:
>> http://news.bbc.co.uk/2/hi/in_depth/sci_tech/2003/denver_2003/
>> 2763657.stm
>>
>> pictures of a monitoring site and the detector:
>> http://news.bbc.co.uk/2/hi/science/nature/1522932.stm
>>
>> a miscellaneous link on infrasound:
>> http://news.bbc.co.uk/2/hi/science/nature/2309505.stm
>>
>> All the BBC articles have additonal links to further reading.
>>
>> Regards,
>> Charles R. Patton
>>
>> __________________________________________________________
>>
>> Public Seismic Network Mailing List (PSN-L)
>>
>> To leave this list email PSN-L-REQUEST@.............. with
>> the body of the message (first line only): unsubscribe
>> See http://www.seismicnet.com/maillist.html for more information.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Amaseis and Dataq DI-151RS
From: "David H. Youden" dyouden@.........
Date: Sun, 16 Feb 2003 16:03:37 -0500
Hello all,
I need a bit of help. I just installed a new copy of Amaseis and I can't
get it to work with my 151RS. I know about the .ini file and I have set the
COM port correctly. Is there some other undocumented setting that I must
make? The documentation from The U of A makes no mention of alternate ADCs.
Thanks for any help you can give me.
Dave...
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Amaseis and Dataq DI-151RS
From: "Steve Hansen" shansen@........
Date: Sun, 16 Feb 2003 21:22:19 -0000
I found this program just last week when I was prepping an old 151RS that I
had laying around for a high school student who was going to use it for a
project.
Here's what my ini file was:
[MRU]
Count=4
[AS1]
Latitude=0
Longitude=0
Elevation=0
BAUD=4800
COM=1
Gain=500
Component=Z
StationName=Station Name
StationCode=SUNYB
FileExtension=LPZ
LinesPerHour=1
DecimateFactor=1
DaysToRetainRecords=10
LowPassCutoff=10
ZeroLevel=2048
InitSampleSeconds=5
SampleRate=10
BandPassLowCutoff=0
BandPassHighCutoff=2
Device=DATAQ151
I think the critical part was putting the correct device name in the last
line.
In the helicorder mode I couldn't get the time axis correct. It would gain
almost a minute for every recorded minute. However, when I closed the
program and restarted it the saved trace would have the correct timing.
Hope this helps.
Steve Hansen
----- Original Message -----
From: "David H. Youden"
To:
Sent: Sunday, February 16, 2003 9:03 PM
Subject: Amaseis and Dataq DI-151RS
> Hello all,
>
> I need a bit of help. I just installed a new copy of Amaseis and I can't
> get it to work with my 151RS. I know about the .ini file and I have set
the
> COM port correctly. Is there some other undocumented setting that I must
> make? The documentation from The U of A makes no mention of alternate
ADCs.
>
> Thanks for any help you can give me.
> Dave...
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: BBC news article about infrasound
From: ChrisAtUpw@.......
Date: Sun, 16 Feb 2003 21:49:12 EST
In a message dated 16/02/03, hernlund@............ writes:
> Because the atmosphere becomes less dense approximately exponentially with
> height, the sound wave velocity decreases.
Hi John,
The velocity of sound in air is primarily proportional to the square
root of the absolute temperature, which of course decreases with height up to
the stratosphere. Pressure has relatively little effect over the atmospheric
range. Dispersion goes roughly with f^2, where f is the frequency, so waves
of a few Hz or less can propagate around the globe. Volcanic explosions may
be detected going around the Earth several times.
Regards,
Chris Chapman
In a message dated 16/02/=
03, hernlund@............ writes:
Because the atmosphere beco=
mes less dense approximately exponentially with height, the sound wave veloc=
ity decreases.
Hi John,
The velocity of sound in air is pri=
marily proportional to the square root of the absolute temperature, which of=
course decreases with height up to the stratosphere. Pressure has relativel=
y little effect over the atmospheric range. Dispersion goes roughly with f^2=
, where f is the frequency, so waves of a few Hz or less can propagate aroun=
d the globe. Volcanic explosions may be detected going around the Earth seve=
ral times.=20
Regards,
Chris Chapman
Subject: Differential Photo Detector
From: John or Jan Lahr johnjan@........
Date: Sun, 16 Feb 2003 21:38:42 -0700
Hi Chris,
I put your messages and schematic for the differential photo detector on the
web here:
http://jjlahr.com/science/psn/chapman/photo_detect/
Let me know if that's OK with you and if there are any changes that I
should make. I left it as a series of E-mail exchanges, and your
schematic is there in gif and pdf formats.
Cheers,
John
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: New WinQuake, WinSDR, GPS Pass-Through and WinPlotGPS releases
From: "Larry Cochrane" cochrane@..............
Date: Sun, 16 Feb 2003 21:31:14 -0800
Hi Everyone,
Sorry if you get this message twice. Since the new releases effect both
WinSDR and WinQuake I'm sending this message to both lists.
WinQuake.
The new beta release, version 2.9.2, can be downloaded from here
http://www.seismicnet.com/wqdocs/wqbeta.html. Here are the highlights of
this release, see the beta release documentation for a complete list:
The program now supports viewing up to three event records in the same event
window. This way the data from a two or three component sensor can be
displayed in the same window. Only event files that have the same
characteristics, start time, sample rate, data points and sensor type
(acceleration, velocity or displacement) can be viewed in the same window.
WinQuake also supports reading and writing dataset volume. A dataset set
volume being two or three event records in one event file. The format of a
dataset volume file is documented here
http://www.seismicnet.com/psnformat4.html#Volume. A volume file has a 10
byte pre-header and then two or three PSNType 4 event files stacked one
after the other.
WinSDR:
The program now supports saving event records in a dataset volume. Datasets
can be viewed with the new WinQuake beta release. See the WinSDR beta
release notes here http://www.seismicnet.com/winsdr/betarelease.html for
more information. I also have a new firmware release for my 16-Bit Serial
Output A/D board. See this link for more information
http://www.seismicnet.com/winsdr/releasenotes.html#Serial. This link
http://www.seismicnet.com/software/rsdr24.zip can be used to download the
new firmware file.
GPS Pass-Through Mode:
The new firmware on the Serial Output A/D board now supports a GPS
pass-through mode. When this mode is enabled, all data on the GPS comm port
is sent out the main Comm port and all data set to the main Comm port will
be sent to the GPS receiver. The GPS Pass-Through mode allows GPS mapping
programs like WinPlotGPS to communicate directly with the GPS receiver
connected up the A/D board. See this link for more information
http://www.seismicnet.com/serialatod.html#GPS%20Pass-Through%20Mode.
WinPlotGPS:
This release fixes several bugs I discovered in the first beta release. The
main bug being a problem with the GPS Message Viewer not displaying
correctly after the program is restored from being minimized. See this page
http://www.seismicnet.com/winplotgps/ from more information on WinPlotGPS.
That's it. Please let me know if you run into any problems with any of the
new programs.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: R: Amaseis and Dataq DI-151RS
From: "Mauro Mariotti" mariotti@.........
Date: Mon, 17 Feb 2003 08:51:35 +0100
Hello,
amasesis should work also with David Saum board.
Vice-versa, dataq should work also with Seismowin
in Infiltec board mode.
regards
Mauro
----- Original Message -----
From: David H. Youden
To:
Sent: Sunday, February 16, 2003 10:03 PM
Subject: Amaseis and Dataq DI-151RS
> Hello all,
>
> I need a bit of help. I just installed a new copy of Amaseis and I can't
> get it to work with my 151RS. I know about the .ini file and I have set
the
> COM port correctly. Is there some other undocumented setting that I must
> make? The documentation from The U of A makes no mention of alternate
ADCs.
>
> Thanks for any help you can give me.
> Dave...
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: BBC news article about infrasound
From: John Hernlund hernlund@............
Date: Mon, 17 Feb 2003 02:29:11 -0800
Hey Chris,
In the ideal gas treatment (this is where the approximate comes in),=20=
the equation of state is just PV=3DnkT where P is pressure, V is volume,=20=
n is number of molecules, k is Boltzman's constant, and T is=20
temperature. This is the same as P=3DrkT where r is the number density.=20=
While this is quite approximate, it does capture the gross features of=20=
the atmosphere surprisingly well. The hydrostatic part of the=20
atmospheric equilibrium (force balance) is determined by dP/dz=20
proportional to -r*g, where g is the gravitational acceleration. At=20
constant T this gives you:
dP/dz proportional to -P*g/kT or upon integrating just P proportional=20
to exp(-z*g/kT) where z is the height. Since P is proportional to r in=20=
this case, then density also falls off exponentially with height.
The temperature of the atmosphere does decrease slightly up to a=20
certain height, but then rockets way up to thousands of Kelvins in the=20=
ionosphere. You can see from the equation of state that at constant=20
pressure, the number density also decreases as temperature increases.=20
At constant temperature, the pressure decreases in proportion to the=20
density. There is obviously a tradeoff between these two end members,=20
which is reflected in the adiabatic (constant entropy) vs isothermal=20
(constant temperature) solutions. But you can certainly see that, no=20
matter what, a decrease in temperature will never lead to a decrease in=20=
density unless pressure is increased in larger proportion, which does=20
not occur in the hydrostatic atmosphere. This is all reflected in a=20
term called the "scale height" of the atmosphere, which is the height=20
at which the density decreases by a factor of 1/e =3D 1/2.7182818... =
For=20
the Earth's atmosphere this is well measured and is (if my memory suits=20=
me well) around 9 kilometers (it is proportional to kT/g from the above=20=
considerations).
Anyways, this is all old news, and was proposed by Pascal some time=20
ago. The idea was that pressure is primarily due to the weight of the=20
atmosphere above you, so that the hypothesis could be tested by=20
carrying a barometer to the top of a mountain and comparing its reading=20=
with the value at the bottom of the mountain. Tests did, of course,=20
confirm this hypothesis.
So why all this fuss about density? Density is the amount of mass=20
contained in a volume, and according to Sir Newton if the mass=20
decreases then the acceleration increases given the same forcing. This=20=
is what really leads to the large amplitudes for vertically propagating=20=
waves...
So your supposition about the temperature dependence being most=20
important is not applicable in this case. I would note, however, that=20
it could be appropriate for sound waves traveling horizontally at a=20
constant altitude where the pressure is about constant, and this is=20
probably what you are thinking about. Horizontal temperature changes=20
will then induce density changes in inverse proportion. This is not=20
part of the hydrostatic atmosphere, but rather is part of the dynamic=20
atmosphere which drives winds, etc.. However, this dynamic part is=20
quite small compared to the static part when vertical directions are=20
considered, much like in the deep Earth. The only exception might be=20
when a tornado comes by, and pressure plummets horizontally very=20
rapidly.
Also note that the ionosphere is quite a bit higher up there beyond the=20=
tropopause, and that the atmosphere does not ever really end but merges=20=
in a complicated way with the solar wind and its nature up there is=20
governed mostly by magnetic field effects. Dispersion in the ionosphere=20=
is complicated by the polarizing effects of moving cations and anions=20
vertically apart creating a virtual capacitance that damps these=20
oscillations.
Cheers!
John
On Sunday, February 16, 2003, at 06:49 PM, ChrisAtUpw@....... wrote:
> In a message dated 16/02/03, hernlund@............ writes:
>
> Because the atmosphere becomes less dense approximately exponentially=20=
> with height, the sound wave velocity decreases.
>
> Hi John,
>
> =A0=A0=A0=A0=A0=A0The velocity of sound in air is primarily =
proportional to the=20
> square root of the absolute temperature, which of course decreases=20
> with height up to the stratosphere. Pressure has relatively little=20
> effect over the atmospheric range. Dispersion goes roughly with f^2,=20=
> where f is the frequency, so waves of a few Hz or less can propagate=20=
> around the globe. Volcanic explosions may be detected going around the=20=
> Earth several times.
>
> =A0=A0=A0=A0=A0=A0Regards,
>
> =A0=A0=A0=A0=A0=A0Chris Chapman=
Hey Chris,
In the ideal gas treatment (this is where the approximate comes
in), the equation of state is just PV=3DnkT where P is pressure, V is
volume, n is number of molecules, k is Boltzman's constant, and T is
temperature. This is the same as P=3DrkT where r is the number density.
While this is quite approximate, it does capture the gross features of
the atmosphere surprisingly well. The hydrostatic part of the
atmospheric equilibrium (force balance) is determined by dP/dz
proportional to -r*g, where g is the gravitational acceleration. At
constant T this gives you:
dP/dz proportional to -P*g/kT or upon integrating just P proportional
to exp(-z*g/kT) where z is the height. Since P is proportional to r in
this case, then density also falls off exponentially with height.
The temperature of the atmosphere does decrease slightly up to a
certain height, but then rockets way up to thousands of Kelvins in the
ionosphere. You can see from the equation of state that at constant
pressure, the number density also decreases as temperature increases.
At constant temperature, the pressure decreases in proportion to the
density. There is obviously a tradeoff between these two end members,
which is reflected in the adiabatic (constant entropy) vs isothermal
(constant temperature) solutions. But you can certainly see that, no
matter what, a decrease in temperature will never lead to a decrease
in density unless pressure is increased in larger proportion, which
does not occur in the hydrostatic atmosphere. This is all reflected in
a term called the "scale height" of the atmosphere, which is the
height at which the density decreases by a factor of 1/e =3D
1/2.7182818... For the Earth's atmosphere this is well measured and
is (if my memory suits me well) around 9 kilometers (it is
proportional to kT/g from the above considerations).
Anyways, this is all old news, and was proposed by Pascal some time
ago. The idea was that pressure is primarily due to the weight of the
atmosphere above you, so that the hypothesis could be tested by
carrying a barometer to the top of a mountain and comparing its
reading with the value at the bottom of the mountain. Tests did, of
course, confirm this hypothesis.
So why all this fuss about density? Density is the amount of mass
contained in a volume, and according to Sir Newton if the mass
decreases then the acceleration increases given the same forcing. This
is what really leads to the large amplitudes for vertically
propagating waves...
So your supposition about the temperature dependence being most
important is not applicable in this case. I would note, however, that
it could be appropriate for sound waves traveling horizontally at a
constant altitude where the pressure is about constant, and this is
probably what you are thinking about. Horizontal temperature changes
will then induce density changes in inverse proportion. This is not
part of the hydrostatic atmosphere, but rather is part of the dynamic
atmosphere which drives winds, etc.. However, this dynamic part is
quite small compared to the static part when vertical directions are
considered, much like in the deep Earth. The only exception might be
when a tornado comes by, and pressure plummets horizontally very
rapidly.
Also note that the ionosphere is quite a bit higher up there beyond
the tropopause, and that the atmosphere does not ever really end but
merges in a complicated way with the solar wind and its nature up
there is governed mostly by magnetic field effects. Dispersion in the
ionosphere is complicated by the polarizing effects of moving cations
and anions vertically apart creating a virtual capacitance that damps
these oscillations.
Cheers!
John
On Sunday, February 16, 2003, at 06:49 PM, ChrisAtUpw@....... wrote:
ArialIn a message dated
16/02/03, hernlund@............ writes:
Because the atmosphere becomes less dense
approximately exponentially with height, the sound wave velocity
decreases.
=
Arial0000,0000,0000Hi
John,
=A0=A0=A0=A0=A0=A0The velocity of sound in air is primarily proportional =
to the
square root of the absolute temperature, which of course decreases
with height up to the stratosphere. Pressure has relatively little
effect over the atmospheric range. Dispersion goes roughly with f^2,
where f is the frequency, so waves of a few Hz or less can propagate
around the globe. Volcanic explosions may be detected going around the
Earth several times.
=A0=A0=A0=A0=A0=A0Regards,
=A0=A0=A0=A0=A0=A0Chris Chapman=
Subject: Re: Amaseis and Dataq DI-151RS
From: "David H. Youden" dyouden@.........
Date: Mon, 17 Feb 2003 06:22:00 -0500
Steve,
Thank you very much! I appreciate the help.
Dave...
At 09:22 PM 2/16/03 +0000, you wrote:
>I found this program just last week when I was prepping an old 151RS that I
>had laying around for a high school student who was going to use it for a
>project.
>
>Here's what my ini file was:
>
>[MRU]
>Count=4
>[AS1]
>Latitude=0
>Longitude=0
>Elevation=0
>BAUD=4800
>COM=1
>Gain=500
>Component=Z
>StationName=Station Name
>StationCode=SUNYB
>FileExtension=LPZ
>LinesPerHour=1
>DecimateFactor=1
>DaysToRetainRecords=10
>LowPassCutoff=10
>ZeroLevel=2048
>InitSampleSeconds=5
>SampleRate=10
>BandPassLowCutoff=0
>BandPassHighCutoff=2
>Device=DATAQ151
>
>I think the critical part was putting the correct device name in the last
>line.
>
>In the helicorder mode I couldn't get the time axis correct. It would gain
>almost a minute for every recorded minute. However, when I closed the
>program and restarted it the saved trace would have the correct timing.
>
>Hope this helps.
>
>Steve Hansen
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: BBC news article about infrasound
From: ChrisAtUpw@.......
Date: Mon, 17 Feb 2003 08:56:11 EST
In a message dated 17/02/03, hernlund@............ writes:
> Hey Chris,
> In the ideal gas treatment (this is where the approximate comes in),
> the equation of state is just PV=nkT where P is pressure, V is volume, n is
> number of molecules, k is Boltzman's constant, and T is temperature. This
> is the same as P=rkT where r is the number density. While this is quite
> approximate, it does capture the gross features of the atmosphere
> surprisingly well. The hydrostatic part of the atmospheric equilibrium
> (force balance) is determined by dP/dz
> proportional to -r*g, where g is the gravitational acceleration. At
> constant T this gives you: dP/dz proportional to -P*g/kT or upon
> integrating just P proportional
> to exp(-z*g/kT) where z is the height. Since P is proportional to r in this
>
Hi John,
This seems to be a rather convoluted and confusing way of expressing a
simple velocity.
I haven't a clue what a number density is supposed to represent. Would
you care to define it please?
It is quite easy to show that the velocity of sound in a gas is given
by c = Sqrt(gamma x P / rho), where gamma is the ratio of the specific heats,
P is the pressure and rho is the density = mass / volume V. Hence PV ---> RT
and you don't have to bother with P and V.
Putting in the equation of state gives c = Sqrt(gamma x R x T / M),
where R is the gas constant, T is the temperature and M is the molecular
weight. None of these is a function of another and the expression should be
roughly correct at all pressures until the mean free path effects /
ionisation etc become dominant factors. See Kaye and Laby, Tables of Physical
and Chemical Constants.
Regards,
Chris Chapman
In a message dated 17/02/=
03, hernlund@............ writes:
Hey Chris,
In the ideal gas treatment (this is where the approxi=
mate comes in), the equation of state is just PV=3DnkT where P is pressure,=20=
V is volume, n is number of molecules, k is Boltzman's constant, and T is te=
mperature. This is the same as P=3DrkT where r is the number density. While=20=
this is quite approximate, it does capture the gross features of the atmosph=
ere surprisingly well. The hydrostatic part of the atmospheric equilibrium (=
force balance) is determined by dP/dz=20
proportional to -r*g, where g is the gravitational acceleration. At cons=
tant T this gives you: dP/dz proportional to -P*g/kT or upon integrating jus=
t P proportional=20
to exp(-z*g/kT) where z is the height. Since P is proportional to r in t=
his case, then density also falls off exponentially with height.
Hi John,
This seems to be a rather convolute=
d and confusing way of expressing a simple velocity.
I haven't a clue what a number dens=
ity is supposed to represent. Would you care to define it please?
It is quite easy to show that the v=
elocity of sound in a gas is given by c =3D Sqrt(gamma x P / rho), where gam=
ma is the ratio of the specific heats, P is the pressure and rho is the dens=
ity =3D mass / volume V. Hence PV ---> RT and you don't have to bother wi=
th P and V.
Putting in the equation of state gi=
ves c =3D Sqrt(gamma x R x T / M), where R is the gas constant, T is the tem=
perature and M is the molecular weight. None of these is a function of anoth=
er and the expression should be roughly correct at all pressures until the m=
ean free path effects / ionisation etc become dominant factors. See Kaye and=
Laby, Tables of Physical and Chemical Constants.=20
Regards,
Chris Chapman
Subject: Atomic Time Source for data logging
From: "Jonathan Peakall" jpeakall@............
Date: Mon, 17 Feb 2003 08:12:22 -0800
Hi All,
I just got a project working that I thought might be of interest to some =
folks here. I needed an accurate time source for several projects =
(including a clock that uses Nixie tubes to display the time, looks VERY =
cool) and Atomic clock modules aren't cheap. So what I did was take a =
Atomic clock module, interfaced it with a PIC 12F675, which then drives =
a 433mHz transmitter. Now, anywhere in the house (err, lab I mean) I =
have an accurate self correcting time base for the price of a 433mHz =
reciver, which is about US$15. Vey flexible can date stamp as well. Very =
simple project, and aside from the atomic clock module, very cheap.
Have fun!
Jonathan
www.madlabs.info
Hi All,
I just got a project working that I =
thought might=20
be of interest to some folks here. I needed an accurate time source for =
several=20
projects (including a clock that uses Nixie tubes to display the time, =
looks=20
VERY cool) and Atomic clock modules aren't cheap. So what I did was take =
a=20
Atomic clock module, interfaced it with a PIC 12F675, which then drives =
a 433mHz=20
transmitter. Now, anywhere in the house (err, lab I mean) I have an =
accurate=20
self correcting time base for the price of a 433mHz reciver, which is =
about=20
US$15. Vey flexible can date stamp as well. Very simple project, and =
aside from=20
the atomic clock module, very cheap.
Have fun!
Jonathan
www.madlabs.info
Subject: Re: New WinQuake, WinSDR, GPS Pass-Through and WinPlotGPS releases
From: "Larry Conklin" lconklin@............
Date: Mon, 17 Feb 2003 12:36:42 -0500
Larry,
Thankyou, thankyou, ...
Just downloaded the latest Winquake beta. The latest changes make an
already great program even greater. Everything seems to work as advertised
and the new features make the program much more convenient to use. I did
notice one very small nit. The files window includes a number that I take
to be the number of files in the open subdirectory. The value shown in two
greater than the number of files in the list. I suspect that the directory
entries for "this directory (dot)" and "parent directory (double dot)" are
getting included in the file total.
Larry Conklin
----- Original Message -----
From: "Larry Cochrane"
To: ;
Sent: Monday, February 17, 2003 12:31 AM
Subject: New WinQuake, WinSDR, GPS Pass-Through and WinPlotGPS releases
> Hi Everyone,
>
> Sorry if you get this message twice. Since the new releases effect both
> WinSDR and WinQuake I'm sending this message to both lists.
>
> WinQuake.
>
> The new beta release, version 2.9.2, can be downloaded from here
> http://www.seismicnet.com/wqdocs/wqbeta.html. Here are the highlights of
> this release, see the beta release documentation for a complete list:
>
> The program now supports viewing up to three event records in the same
event
> window. This way the data from a two or three component sensor can be
> displayed in the same window. Only event files that have the same
> characteristics, start time, sample rate, data points and sensor type
> (acceleration, velocity or displacement) can be viewed in the same window.
> WinQuake also supports reading and writing dataset volume. A dataset set
> volume being two or three event records in one event file. The format of a
> dataset volume file is documented here
> http://www.seismicnet.com/psnformat4.html#Volume. A volume file has a 10
> byte pre-header and then two or three PSNType 4 event files stacked one
> after the other.
>
> WinSDR:
>
> The program now supports saving event records in a dataset volume.
Datasets
> can be viewed with the new WinQuake beta release. See the WinSDR beta
> release notes here http://www.seismicnet.com/winsdr/betarelease.html for
> more information. I also have a new firmware release for my 16-Bit Serial
> Output A/D board. See this link for more information
> http://www.seismicnet.com/winsdr/releasenotes.html#Serial. This link
> http://www.seismicnet.com/software/rsdr24.zip can be used to download the
> new firmware file.
>
> GPS Pass-Through Mode:
>
> The new firmware on the Serial Output A/D board now supports a GPS
> pass-through mode. When this mode is enabled, all data on the GPS comm
port
> is sent out the main Comm port and all data set to the main Comm port will
> be sent to the GPS receiver. The GPS Pass-Through mode allows GPS mapping
> programs like WinPlotGPS to communicate directly with the GPS receiver
> connected up the A/D board. See this link for more information
> http://www.seismicnet.com/serialatod.html#GPS%20Pass-Through%20Mode.
>
> WinPlotGPS:
>
> This release fixes several bugs I discovered in the first beta release.
The
> main bug being a problem with the GPS Message Viewer not displaying
> correctly after the program is restored from being minimized. See this
page
> http://www.seismicnet.com/winplotgps/ from more information on WinPlotGPS.
>
> That's it. Please let me know if you run into any problems with any of the
> new programs.
>
> Regards,
> Larry Cochrane
> Redwood City, PSN
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: BBC news article about infrasound
From: John Hernlund hernlund@............
Date: Mon, 17 Feb 2003 12:28:05 -0800
On Monday, February 17, 2003, at 05:56 AM, ChrisAtUpw@....... wrote:
> In a message dated 17/02/03, hernlund@............ writes:
>
> Hey Chris,
> =A0=A0=A0In the ideal gas treatment (this is where the approximate =
comes=20
> in), the equation of state is just PV=3DnkT where P is pressure, V is=20=
> volume, n is number of molecules, k is Boltzman's constant, and T is=20=
> temperature. This is the same as P=3DrkT where r is the number =
density.=20
> While this is quite approximate, it does capture the gross features of=20=
> the atmosphere surprisingly well. The hydrostatic part of the=20
> atmospheric equilibrium (force balance) is determined by dP/dz
> proportional to -r*g, where g is the gravitational acceleration. At=20
> constant T this gives you: dP/dz proportional to -P*g/kT or upon=20
> integrating just P proportional
> to exp(-z*g/kT) where z is the height. Since P is proportional to r in=20=
> this case, then density also falls off exponentially with height.
>
> Hi John,
>
> =A0=A0=A0=A0=A0=A0This seems to be a rather convoluted and confusing =
way of=20
> expressing a simple velocity.
Well...sorry about that...I tend to be quite convoluted when writing=20
e-mails late at night, and my thinking was obviously not clear (see=20
below).
> =A0=A0=A0=A0=A0=A0I haven't a clue what a number density is supposed =
to represent.=20
> Would you care to define it please?
If you do the algebra:
PV=3DnkT
P=3DrkT
then r=3Dn/V or the number of molecules per unit volume.
> =A0=A0=A0=A0=A0=A0It is quite easy to show that the velocity of sound =
in a gas is=20
> given by c =3D Sqrt(gamma x P / rho), where gamma is the ratio of the=20=
> specific heats, P is the pressure and rho is the density =3D mass /=20
> volume V. Hence PV ---> RT and you don't have to bother with P and V.
Yes, the sound speed is Sqrt(dP/drho) and under the assumptions of=20
adiabatic fluctuations you do get this expression. You are correct=20
about the sound speed, and after going through some simple derivations,=20=
I see that the growth in amplitude with height is not due to slowing=20
down of waves, but rather is about the density only. To make this more=20=
explicit (and hopefully not so convoluted), I'll explain this briefly=20
below:
The sound wave equation for a wave going upward (z) can be written in=20
terms of density (rho) as:
d[ln(rho)]/dt=3D-c*d[ln(rho)]/dz
and the solution is just the equation ln(rho)=3Df(z-c*t), where f(z) is=20=
the function describing the wave's profile that depends only on the=20
initial perturbations at t=3D0.
You find the true origin of the amplitude increase with height by=20
separating the density into a hydrostatic part rho' (a function of z=20
only) times a factor measuring the fluctuation, that is:
rho=3D(q+1)*rho'
where q+1 is the fluctuation factor. For example, if q=3D0.10 then this=20=
represents a ten percent increase in density relative to the=20
hydrostatic density while q=3D0 represents no density fluctuation. You=20=
now get, since the time dependence of rho' goes away:
d[ln(q+1)]/dt=3D-c*d[ln(q+1)]/dz-c*d[ln(rho')]/dz
Since rho' decreases exponentially with height as=20
rho'(z)=3Drho'(z=3D0)*exp(-z/H), where H is the scale height, then the =
wave=20
equation says that:
d[ln(q+1)]/dt=3D-c*d[ln(q+1)]/dz+(c/H),
So looking just at the first term on the right side, it represents a=20
wave traveling upward with no change in fluctuation amplitude,
d[ln(q+1)]/dt=3D-c*d[ln(q+1)]/dz,
with a solution,
ln(q+1)=3Df(z-c*t) + a constant.
while the second term represents a source that increases ln(q+1) by an=20=
amount (c/H) per unit time,
d[ln(q+1)]/dt=3D(c/H),
which has the solution,
ln(q+1) =3D t*c/H + a constant
This second term is the origin of the growing amplitudes, it is not a=20
slowing down of waves that causes this. The surprising thing is the=20
exponential increase in fluctuation q with time. If we take H=3D9000=20
meters, as a typical parameter, and by noting that c*t is ~ the=20
distance the wave has traveled,
ln(q+1) =3D z/H + ln[q(z=3D0)+1],
or,
q+1 =3D [q(z=3D0)+1]*exp(z/H)
So at the scale height (~9 km), the fluctuation factor q+1 has=20
increased by ~2.7 (density due to wave fluctuation is 2.7 times more or=20=
less than its static value), at two scale heights it increases by ~7.3=20=
, at three it is ~19.7, four ~53.1, etc.. Of course, when you get up to=20=
the ionosphere you have gone about 10 scale heights so the fluctuation=20=
factor has increased by ~22,000 or more. It sounds reasonable then,=20
that this is how you get 100 m displacements from small EQ or tsunami=20
motions at the surface that aren't very large at all.
So the physics still holds up, all this stuff above simply means that a=20=
decreasing mass (density) means that for the same energy in a traveling=20=
wave that the amplitude must increase...simply due to inertia and the=20
the exponential decrease of density.
I recently saw an interesting related story (brief blurb on cnn) that=20
satellites are trying to measure the hissing sound produced by spray=20
paint cans in LA to prevent graffiti...don't know how well this will=20
work.
Cheers!
John
On Monday, February 17, 2003, at 05:56 AM, ChrisAtUpw@....... wrote:
ArialIn a message dated
17/02/03, hernlund@............ writes:
Hey Chris,
=A0=A0=A0In the ideal gas treatment (this is where the approximate comes
in), the equation of state is just PV=3DnkT where P is pressure, V is
volume, n is number of molecules, k is Boltzman's constant, and T is
temperature. This is the same as P=3DrkT where r is the number density.
While this is quite approximate, it does capture the gross features of
the atmosphere surprisingly well. The hydrostatic part of the
atmospheric equilibrium (force balance) is determined by dP/dz
proportional to -r*g, where g is the gravitational acceleration. At
constant T this gives you: dP/dz proportional to -P*g/kT or upon
integrating just P proportional
to exp(-z*g/kT) where z is the height. Since P is proportional to r in
this case, then density also falls off exponentially with height.
Hi John,
=A0=A0=A0=A0=A0=A0This seems to be a rather convoluted and confusing way =
of
expressing a simple velocity.
Well...sorry about that...I tend to be quite convoluted when writing
e-mails late at night, and my thinking was obviously not clear (see
below).
=A0=A0=A0=A0=A0=A0I haven't a clue what a number density is =
supposed to
represent. Would you care to define it please?
If you do the algebra:
PV=3DnkT
P=3DrkT
then r=3Dn/V or the number of molecules per unit volume.
=A0=A0=A0=A0=A0=A0It is quite easy to show that the velocity of =
sound in
a gas is given by c =3D Sqrt(gamma x P / rho), where gamma is the ratio
of the specific heats, P is the pressure and rho is the density =3D mass
/ volume V. Hence PV ---> RT and you don't have to bother with P and V.
Yes, the sound speed is Sqrt(dP/drho) and under the assumptions of
adiabatic fluctuations you do get this expression. You are correct
about the sound speed, and after going through some simple
derivations, I see that the growth in amplitude with height is not due
to slowing down of waves, but rather is about the density only. To
make this more explicit (and hopefully not so convoluted), I'll
explain this briefly below:
The sound wave equation for a wave going upward (z) can be written in
terms of density (rho) as:
d[ln(rho)]/dt=3D-c*d[ln(rho)]/dz
and the solution is just the equation ln(rho)=3Df(z-c*t), where f(z) is
the function describing the wave's profile that depends only on the
initial perturbations at t=3D0.
You find the true origin of the amplitude increase with height by
separating the density into a hydrostatic part rho' (a function of z
only) times a factor measuring the fluctuation, that is:
rho=3D(q+1)*rho'
where q+1 is the fluctuation factor. For example, if q=3D0.10 then this
represents a ten percent increase in density relative to the
hydrostatic density while q=3D0 represents no density fluctuation. You
now get, since the time dependence of rho' goes away:
d[ln(q+1)]/dt=3D-c*d[ln(q+1)]/dz-c*d[ln(rho')]/dz
Since rho' decreases exponentially with height as
rho'(z)=3Drho'(z=3D0)*exp(-z/H), where H is the scale height, then the
wave equation says that:
d[ln(q+1)]/dt=3D-c*d[ln(q+1)]/dz+(c/H),
So looking just at the first term on the right side, it represents a
wave traveling upward with no change in fluctuation amplitude,
d[ln(q+1)]/dt=3D-c*d[ln(q+1)]/dz,
with a solution,
ln(q+1)=3Df(z-c*t) + a constant.
while the second term represents a source that increases ln(q+1) by an
amount (c/H) per unit time,
d[ln(q+1)]/dt=3D(c/H),
which has the solution,
ln(q+1) =3D t*c/H + a constant
This second term is the origin of the growing amplitudes, it is not a
slowing down of waves that causes this. The surprising thing is the
exponential increase in fluctuation q with time. If we take H=3D9000
meters, as a typical parameter, and by noting that c*t is ~ the
distance the wave has traveled,
ln(q+1) =3D z/H + ln[q(z=3D0)+1],
or,
q+1 =3D [q(z=3D0)+1]*exp(z/H)
So at the scale height (~9 km), the fluctuation factor q+1 has
increased by ~2.7 (density due to wave fluctuation is 2.7 times more
or less than its static value), at two scale heights it increases by
~7.3 , at three it is ~19.7, four ~53.1, etc.. Of course, when you get
up to the ionosphere you have gone about 10 scale heights so the
fluctuation factor has increased by ~22,000 or more. It sounds
reasonable then, that this is how you get 100 m displacements from
small EQ or tsunami motions at the surface that aren't very large at
all.
So the physics still holds up, all this stuff above simply means that
a decreasing mass (density) means that for the same energy in a
traveling wave that the amplitude must increase...simply due to
inertia and the the exponential decrease of density.
I recently saw an interesting related story (brief blurb on cnn) that
satellites are trying to measure the hissing sound produced by spray
paint cans in LA to prevent graffiti...don't know how well this will
work.
Cheers!
John
Subject: Winquake bug
From: "Larry Conklin" lconklin@............
Date: Mon, 17 Feb 2003 15:48:49 -0500
Hi Larry,
Spent a little more time with the new Winquake update and found a problem
with the Y-scale function. If I select the "Use as default" option, I can
open as many pairs of files as I like, as long as I don't exit the program.
However, if I close the program with that option selected, the next time I
run it, it hangs up when I try to open even a single file. I have to do a
three finger salute to kill the program and regain control. I discovered
that if I inspect the Winquake.ini file and edit the YDefOnOff parameter to
reset it to zero, the next time I start Winquake everything is ok. I had
also set the "All Records" option to True, but that doesn't seem to affect
the problem one way or the other.
Larry Conklin
lconklin@............
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: new winsdr with remote function of wq
From: "Francesco" fra.nuc@...........
Date: Mon, 17 Feb 2003 22:17:36 +0100
Hi Larry.
I've upgrade my system with new releases of WS and Wq, setting it with
dataset feature.
If I want use the remote option in Winquake, what I have to change? The file
extention of the three components in remote box must be the same?
Regards
Francesco Italy
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake, WinSDR, GPS Pass-Through and WinPlotGPS releases
From: RLLaney@.......
Date: Mon, 17 Feb 2003 17:28:51 EST
In a message dated 2/16/03 9:31:57 PM Pacific Standard Time,
cochrane@.............. writes:
> The program now supports viewing up to three event records in the same event
> window.
Hi Larry:
Winquake only improves! This option to view more than one event in the same
window is great. Just one question so far. When more than one event file is
viewed in the same window, no file labels appear. When viewing on the
monitor, of course, one need only to click on a file and it reads out on the
window bar to distinguish between the event files. When more than one file
is printed from the same window, however, no labels appear. Is this an easy
fix?
Many thanks.
Bob Laney
Salem, Oregon
In a message dated 2/16/03 9:31:57 PM Pacific Standard=
Time, cochrane@.............. writes:
The program now supports viewin=
g up to three event records in the same event
window.
Hi Larry:
Winquake only improves! This option to view more than one event in the=
same window is great. Just one question so far. When more than=20=
one event file is viewed in the same window, no file labels appear. Wh=
en viewing on the monitor, of course, one need only to click on a file and i=
t reads out on the window bar to distinguish between the event files. =20=
When more than one file is printed from the same window, however, no labels=20=
appear. Is this an easy fix?
Many thanks.
Bob Laney
Salem, Oregon
Subject: Re: New WinQuake, WinSDR, GPS Pass-Through and WinPlotGPS releases
From: RLLaney@.......
Date: Mon, 17 Feb 2003 17:34:01 EST
In a message dated 2/16/03 9:31:57 PM Pacific Standard Time,
cochrane@.............. writes:
> The program now supports viewing up to three event records in the same event
> window.
Correction, Larry, to my just sent email--a label appears when multiple event
files are printed, but only the label for the highlighted event files appears
at the top of the page.
Bob
In a message dated 2/16/03 9:31:57 PM Pacific Standard=
Time, cochrane@.............. writes:
The program now supports viewin=
g up to three event records in the same event
window.
Correction, Larry, to my just sent email--a label appears when multiple even=
t files are printed, but only the label for the highlighted event files appe=
ars at the top of the page.
Bob
Subject: Re: Various Winquake bugs
From: "Larry Cochrane" cochrane@..............
Date: Mon, 17 Feb 2003 19:39:31 -0800
From: "Larry Conklin"
> Hi Larry,
>
> Spent a little more time with the new Winquake update and found a problem
> with the Y-scale function. If I select the "Use as default" option, I can
> open as many pairs of files as I like, as long as I don't exit the
program.
> However, if I close the program with that option selected, the next time I
> run it, it hangs up when I try to open even a single file. I have to do a
> three finger salute to kill the program and regain control. I discovered
> that if I inspect the Winquake.ini file and edit the YDefOnOff parameter
to
> reset it to zero, the next time I start Winquake everything is ok. I had
> also set the "All Records" option to True, but that doesn't seem to affect
> the problem one way or the other.
I fixed this bug and the other one you reported regarding the number of
files displayed in the Open File dialog box.
From: "Francesco"
> Hi Larry.
> I've upgrade my system with new releases of WS and Wq, setting it with
> dataset feature.
> If I want use the remote option in Winquake, what I have to change? The
file
> extention of the three components in remote box must be the same?
Good question! I'm working on a new release that will allow WinQuake to
request dataset volume files. This change will effect both WinQuake and
WinSDR. Also, the Event File Mailer program I released sometime last year
also needs to be updated to support dataset volumes.
From: RLLaney@.......
>Correction, Larry, to my just sent email--a label appears when multiple
event files
>are printed, but only the label for the highlighted event files appears at
the top of the page.
That's an easy one to correct. The next release will display all of the file
names when you print the event window or create a GIF image.
I should have new WinQuake and WinSDR release ready later tonight or
tomorrow.
Regards,
Larry Cochrane
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Earth monitors recorded explosions on Columbia
From: "Erich Kern" efkern@.............
Date: Mon, 17 Feb 2003 20:17:19 -0800
Investigating infrasound recordings and the possibility of a 'blue sprite' electrical
discharge.
http://wnd.com/news/article.asp?ARTICLE_ID=31066
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: WQ zoom in 2.9.2 v.
From: "Francesco" fra.nuc@...........
Date: Tue, 18 Feb 2003 22:50:08 +0100
It's no more possible save the event with zoom option, in the last version?
There isn't the check box...
Regards
Francesco Italy
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WQ zoom in 2.9.2 v.
From: "Larry Cochrane" cochrane@..............
Date: Tue, 18 Feb 2003 14:17:26 -0800
Hi Francesco,
Use the new crop feature (View / Crop menu items) and then save the file. I
removed the View Only check box in the File Save dialog box since the crop
feature does the same thing.
Regards,
Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Francesco"
To:
Sent: Tuesday, February 18, 2003 1:50 PM
Subject: WQ zoom in 2.9.2 v.
> It's no more possible save the event with zoom option, in the last
version?
> There isn't the check box...
>
> Regards
>
> Francesco Italy
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: WinQuake 2.9.2
From: "Bob Hancock" robert.hancock@...........
Date: Tue, 18 Feb 2003 17:46:26 -0500
Larry -
As everyone says, this version will probably make professional seismologists
wonder why they don't have something that nice.
Just one question, as I played with the new program, and had 3 files
displayed, I found I could only run the FFT option on one file. Either the
three program option was designed to work with files that have already been
through the FFT option, or I missed something in WinQuake 101.......Can you
verify or amplify.
Thanks,
Bob Hancock
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinQuake 2.9.2
From: "Larry Cochrane" cochrane@..............
Date: Tue, 18 Feb 2003 15:23:29 -0800
Bob,
Right now WinQuake only displays an FFT of the currently highlighted record.
In the future I will modify the FFT Window to display two or threes FFT
sub-windows.
-Larry
----- Original Message -----
From: "Bob Hancock"
To: "psn-l@........... com (E-mail)"
Sent: Tuesday, February 18, 2003 2:46 PM
Subject: WinQuake 2.9.2
> Larry -
>
> As everyone says, this version will probably make professional
seismologists
> wonder why they don't have something that nice.
>
> Just one question, as I played with the new program, and had 3 files
> displayed, I found I could only run the FFT option on one file. Either
the
> three program option was designed to work with files that have already
been
> through the FFT option, or I missed something in WinQuake 101.......Can
you
> verify or amplify.
>
> Thanks,
>
> Bob Hancock
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Atomic Time Source for data logging
From: ChrisAtUpw@.......
Date: Wed, 19 Feb 2003 00:23:00 EST
In a message dated 17/02/03, jpeakall@............ writes:
> So what I did was take a Atomic clock module, interfaced it with a PIC
> 12F675, which then drives a 433mHz transmitter.
Hi Jonathan,
What are atomic clock modules, please and do you have a source? I am
familiar with WWV and WWVS time signals and time clocks which use them.
Oregon Scientific supply radio clocks which use atomic time standards.
Genuine Rubidium and Caesium clocks are Kilobucks.
Regards,
Chris Chapman
In a message dated 17/02/=
03, jpeakall@............ writes:
So what I did was take a At=
omic clock module, interfaced it with a PIC 12F675, which then drives a 433m=
Hz transmitter.
Hi Jonathan,
What are atomic clock modules, plea=
se and do you have a source? I am familiar with WWV and WWVS time signals an=
d time clocks which use them. Oregon Scientific supply radio clocks which us=
e atomic time standards.
Genuine Rubidium and Caesium clocks=
are Kilobucks.
Regards,=20
Chris Chapman
Subject: Re: Atomic Time Source for data logging
From: "Jonathan Peakall" jpeakall@............
Date: Wed, 19 Feb 2003 07:06:18 -0800
Chris,
Well, actually, I just took a chunk of ceasium, put it in a coffee can =
and got one of those GI radiation counters. The only real problem is the =
glow at night in my bedroom...
The Atomic Clock module is a WWVB receiver/decoder. It also has an =
onboard time source which is corrected as often as the WWVB signal is =
recieved. It outputs in packed hex which is convienent and small. Sorry =
if the word "module" threw you off.
The one I used is no longer in production. The company makes another one =
for around $160 bucks called the 325B. I have the 321B. If you go to the =
website the product isn't listed there because of legal hassels they are =
having with someone re-marking and selling it. Anyway, he said if folks =
wrote and mentioned me he would still sell them.
The company : http://www.ulio.com/
Email: rod@........
I had a shot at hacking an Oregon Scientific and a Klockit atomic clock =
movements. The signal reception for both was poor. (I live in "black =
hole" for RF) I got the corrected PPS out of them easily, but date, =
pending leap second, leap year and so on was beyond me, partially due to =
signal strength (clockit) and partly due to my (lack of) ability =
(O.scientific), so I'm sure a smarter monkey could make it work.
BTW, I guess my messages are showing up, although I never see them. I do =
get the confirmation post. This happen to anyone else?
Jonathan
www.madlabs.info
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Sent: Tuesday, February 18, 2003 9:23 PM
Subject: Re: Atomic Time Source for data logging
In a message dated 17/02/03, jpeakall@............ writes:=20
So what I did was take a Atomic clock module, interfaced it with a =
PIC 12F675, which then drives a 433mHz transmitter.=20
Hi Jonathan,=20
What are atomic clock modules, please and do you have a source? =
I am familiar with WWV and WWVS time signals and time clocks which use =
them. Oregon Scientific supply radio clocks which use atomic time =
standards.=20
Genuine Rubidium and Caesium clocks are Kilobucks.=20
Regards,=20
Chris Chapman=20
Chris,
Well, actually, I just took a chunk of =
ceasium, put=20
it in a coffee can and got one of those GI radiation counters. The only =
real=20
problem is the glow at night in my bedroom...
The Atomic Clock module is a WWVB =
receiver/decoder.=20
It also has an onboard time source which is corrected as often as the =
WWVB=20
signal is recieved. It outputs in packed hex which is convienent and =
small.=20
Sorry if the word "module" threw you off.
The one I used is no longer in =
production. The=20
company makes another one for around $160 bucks called the 325B. I have =
the=20
321B. If you go to the website the product isn't listed there because of =
legal=20
hassels they are having with someone re-marking and selling it. Anyway, =
he said=20
if folks wrote and mentioned me he would still sell them.
The company : http://www.ulio.com/
Email: rod@........
I had a shot at hacking an Oregon =
Scientific and a=20
Klockit atomic clock movements. The signal reception for both was poor. =
(I live=20
in "black hole" for RF) I got the corrected PPS out of them easily, but =
date,=20
pending leap second, leap year and so on was beyond me, partially due to =
signal=20
strength (clockit) and partly due to my (lack of) ability =
(O.scientific), so I'm=20
sure a smarter monkey could make it work.
BTW, I guess my messages are showing =
up, although I=20
never see them. I do get the confirmation post. This happen to anyone=20
else?
So what I did was take a Atomic clock module, interfaced =
it with=20
a PIC 12F675, which then drives a 433mHz transmitter.
Hi Jonathan,=20
What are atomic clock =
modules,=20
please and do you have a source? I am familiar with WWV and WWVS time =
signals=20
and time clocks which use them. Oregon Scientific supply radio clocks =
which=20
use atomic time standards. =
Genuine=20
Rubidium and Caesium clocks are Kilobucks.=20
Regards,=20
Chris Chapman=20
Subject: Re: Atomic Time Source for data logging
From: BOB BARNS royb1@...........
Date: Wed, 19 Feb 2003 10:58:23 -0500
Hi gang,
Rubidium oscillators (which output 10 MHz pretty near exactly) appear
on ebay perhaps once a month on average.
I looked today with the search string of "rubidium" and found:
Ball Efratom 10MHZ Rubidium Oscillator
Item # 2508157686 5 hrs to go
Efratom Rubidium Oscillator
Item # 2508598369 2 days to go
Efratom Rubidium Oscillator
Item # 2508598561 2 days to go
Austron 1295D Chassis w/ Rubidium Reference
Item # 2509678516 6 days to go
These things usually go for $300-$400 and are easy to use. Usually a
24V DC power supply is needed.
I believe that the useful life of these things is very long (maybe 20
yrs. ?)so getting a used one should be OK.
I remember that Larry hacked a Klockit "atomic clock" to get a 1 PPS
signal to use with his amplifier board or A/D board. Maybe Larry can
supply the reference.
Bob
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Confirmation messages was Atomic Time Source for data logging
From: "Larry Cochrane" cochrane@..............
Date: Wed, 19 Feb 2003 13:16:11 -0800
From: Jonathan Peakall
>BTW, I guess my messages are showing up, although I never see them. I do
get the
>confirmation post. This happen to anyone else?
Jonathan and others,
When you post a message to the PSN-L list all you will get back from my
server is a confirmation message. You will not receive a copy of the message
you sent to the list.
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Atomic Time Source for data logging
From: "Larry Cochrane" cochrane@..............
Date: Wed, 19 Feb 2003 13:34:14 -0800
Bob Barns wrote:
> I remember that Larry hacked a Klockit "atomic clock" to get a 1 PPS
> signal to use with his amplifier board or A/D board. Maybe Larry can
> supply the reference.
I hacked one of Radio Shakes WWVB clocks. This was several years ago, so I'm
not sure if they even sell the clock any more. Here's a link to the web page
documenting what I did with the clock
http://www.seismicnet.com/wwvbsdr.html
Regards,
Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Atomic Time Source for data logging
From: ChrisAtUpw@.......
Date: Wed, 19 Feb 2003 19:41:43 EST
Hi Larry,
HKW Electronic in Gremany sell a range of Receiver Modules and
Decoders for 77.5 KHz, 60 KHz and 40 KHz. They list a decoder for WWVB, but
do not seem to have an agent in the USA. See http://www.hkw-elektronik.de/
I have used the 77.5 and 60 KHz versions of their receivers and the
sensitivity is excellent. You can get problems from Radio Interference in
Urban surroundings, particularly during the day when the signal is weaker and
also from computer monitors. Local lightning can also cause problems, but
this tend to die out during the night. I have tested the response at 2000 km
range and got good daytime signals in mountain surroundings which had low
signal levels, but were free from RFI. The 60 KHz Receiver Module MK68 + MK72
retails at about US $34 + Tax from www.maplin.co.uk They may be cheaper in
Germany.
Regards,
Chris Chapman
Hi Larry,
HKW Electronic in Gremany sell a ra=
nge of Receiver Modules and Decoders for 77.5 KHz, 60 KHz and 40 KHz. They l=
ist a decoder for WWVB, but do not seem to have an agent in the USA. See htt=
p://www.hkw-elektronik.de/=20
I have used the 77.5 and 60 KHz ver=
sions of their receivers and the sensitivity is excellent. You can get probl=
ems from Radio Interference in Urban surroundings, particularly during the d=
ay when the signal is weaker and also from computer monitors. Local lightnin=
g can also cause problems, but this tend to die out during the night. I have=
tested the response at 2000 km range and got good daytime signals in mounta=
in surroundings which had low signal levels, but were free from RFI. The 60=20=
KHz Receiver Module MK68 + MK72 retails at about US $34 + Tax from www.mapli=
n.co.uk They may be cheaper in Germany.
Regards,
Chris Chapman
Subject: New WinQuake and WinSDR Beta Releases
From: "Larry Cochrane" cochrane@..............
Date: Wed, 19 Feb 2003 20:01:34 -0800
Hi Everyone,
I just finished releasing new version of WinQuake, WinSDR and Event File
Mailer. The new releases fix a few problems related to the new PSN dataset
volume files.
In WinSDR, the request file feature has been modified to first look for
dataset volume names and then individual channels IDs. This was need so
WinQuake could request a dataset volume file instead of an individual
channel file. In fact, you must specify the dataset name in WinQuake rather
then one of the channels in the dataset for the Replay or Remote functions
to work correctly. Here's the link to download the new beta release
http://www.seismicnet.com/winsdr/betarelease.html. The new version is 2.0.8
Beta 3.
WinQuake also need modifications to correctly support the Replay and Remote
file request features. I also fixed a few problems reported by the beta
tester. The new release, version 2.9 Beta 3, can be downloaded from here
http://www.seismicnet.com/wqdocs/wqbeta.html.
Lastly, I modified Event File Mailer (EFM) to also support dataset volume
requests. EFM is a program that WinSDR users can run to allow WinQuake to
request event files over the internet. It does this via email messages. See
this page for more information http://www.seismicnet.com/eventfilemailer/.
Regards,
Larry Cochrane
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Atomic Time Source for data logging
From: "Jonathan Peakall" jpeakall@............
Date: Fri, 21 Feb 2003 07:08:57 -0800
Chris,
Neat looking units. Have you interfaced a micro with these? If so, what =
micro did you use? What format/baud rate does the data come in?
Jonathan
www.madlabs.info
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Sent: Wednesday, February 19, 2003 4:41 PM
Subject: Re: Atomic Time Source for data logging
Hi Larry,=20
HKW Electronic in Gremany sell a range of Receiver Modules and =
Decoders for 77.5 KHz, 60 KHz and 40 KHz. They list a decoder for WWVB, =
but do not seem to have an agent in the USA. See =
http://www.hkw-elektronik.de/=20
I have used the 77.5 and 60 KHz versions of their receivers and =
the sensitivity is excellent. You can get problems from Radio =
Interference in Urban surroundings, particularly during the day when the =
signal is weaker and also from computer monitors. Local lightning can =
also cause problems, but this tend to die out during the night. I have =
tested the response at 2000 km range and got good daytime signals in =
mountain surroundings which had low signal levels, but were free from =
RFI. The 60 KHz Receiver Module MK68 + MK72 retails at about US $34 + =
Tax from www.maplin.co.uk They may be cheaper in Germany.=20
Regards,=20
Chris Chapman=20
Chris,
Neat looking units. Have you interfaced =
a micro=20
with these? If so, what micro did you use? What format/baud rate does =
the data=20
come in?
Subject: Re: Atomic Time Source =
for data=20
logging
Hi Larry,=20
HKW Electronic in Gremany =
sell a=20
range of Receiver Modules and Decoders for 77.5 KHz, 60 KHz and 40 =
KHz. They=20
list a decoder for WWVB, but do not seem to have an agent in the USA. =
See http://www.hkw-elektronik.de/ =
I have used the 77.5 and =
60 KHz=20
versions of their receivers and the sensitivity is excellent. You can =
get=20
problems from Radio Interference in Urban surroundings, particularly =
during=20
the day when the signal is weaker and also from computer monitors. =
Local=20
lightning can also cause problems, but this tend to die out during the =
night.=20
I have tested the response at 2000 km range and got good daytime =
signals in=20
mountain surroundings which had low signal levels, but were free from =
RFI. The=20
60 KHz Receiver Module MK68 + MK72 retails at about US $34 + Tax from=20
www.maplin.co.uk They may be cheaper in Germany.=20
Regards,=20
Chris Chapman=20
Subject: Re: Atomic Time Source for data logging
From: ChrisAtUpw@.......
Date: Fri, 21 Feb 2003 20:45:27 EST
In a message dated 21/02/03, jpeakall@............ writes:
> Neat looking units. Have you interfaced a micro with these? If so, what
>
Hi Jonathan,
If you call up http://www.hkw-elektronik.de/pdf/fbw13010_dd.pdf you
will get a description of the WWVB receiver. It can be configured to give +ve
or -ve output pulses following the format of the WWVB signal, which are of 1
pulse per second, but different lengths. There is an AVC line which follows
the signal strength and provides the zero signal level reference. Note that a
crystal filter is used, which provides very narrow band reception. HKW also
do a decoder chip which takes in the signal and gives out RS232. Note that
WWVB, MSF, DCF and JJY are all different time formats. Two ferrite rod
aerials are available, 60 mm or 100 mm long.
Larry has a note on WWVB at http://www.seismicnet.com/wwvbsdr.html and
has modified software to drive the card. Boulder give a time accuracy to
within 0.1 milli second with a good receiver. The errors due to changes in
radio signal path are generally much less that with WWV.
I do not know if these very narrow band receivers will work all over
the US, but Boulder have increased the transmitter power to 50 KW. Maine is
about 1900 m from Boulder, so it must be getting near the limit. I use DCF
and it is very reliable, but I am only about 650 km from the transmitter ~400
m. Night time reception of DCF is quoted to 3000 km ~1900 m and daytime
reception to 2000 km, which I can confirm. I checked my receiver sensitivity
and to stop it working, I had to put it in a tin box and close the lid. And
there are places in my house where you cannot get FM or even good MW radio
reception. These very long wave signals seem to bend around mountains fairly
well. I suggest that you look up http://www.boulder.nist.gov/timefreq/ for a
lot more useful information.
Regards,
Chris Chapman
In a message dated 21/02/=
03, jpeakall@............ writes:
Neat looking units. Have yo=
u interfaced a micro with these? If so, what micro did you use? What format/=
baud rate does the data come in?
Hi Jonathan,
If you call up http://www.hkw-elekt=
ronik.de/pdf/fbw13010_dd.pdf you will get a description of the WWVB receiver=
.. It can be configured to give +ve or -ve output pulses following the format=
of the WWVB signal, which are of 1 pulse per second, but different lengths.=
There is an AVC line which follows the signal strength and provides the zer=
o signal level reference. Note that a crystal filter is used, which provides=
very narrow band reception. HKW also do a decoder chip which takes in the s=
ignal and gives out RS232. Note that WWVB, MSF, DCF and JJY are all differen=
t time formats. Two ferrite rod aerials are available, 60 mm or 100 mm long.=
Larry has a note on WWVB at http://=
www.seismicnet.com/wwvbsdr.html and has modified software to drive the card.=
Boulder give a time accuracy to within 0.1 milli second with a good receive=
r. The errors due to changes in radio signal path are generally much less th=
at with WWV.
I do not know if these very narrow=20=
band receivers will work all over the US, but Boulder have increased the tra=
nsmitter power to 50 KW. Maine is about 1900 m from Boulder, so it must be g=
etting near the limit. I use DCF and it is very reliable, but I am only abou=
t 650 km from the transmitter ~400 m. Night time reception of DCF is quoted=20=
to 3000 km ~1900 m and daytime reception to 2000 km, which I can confirm. I=20=
checked my receiver sensitivity and to stop it working, I had to put it in a=
tin box and close the lid. And there are places in my house where you canno=
t get FM or even good MW radio reception. These very long wave signals seem=20=
to bend around mountains fairly well. I suggest that you look up http://www.=
boulder.nist.gov/timefreq/ for a lot more useful information.
Regards,
Chris Chapman
Subject: Re: Atomic Time Source for data logging
From: "Barry" gbl@.......
Date: Fri, 21 Feb 2003 18:52:50 -0800
Hi All
I have been using the Radio Shack unit as Larry described for quit a while
and it works fine.
Regards
Barry
>
> I hacked one of Radio Shakes WWVB clocks. This was several years ago, so
I'm
> not sure if they even sell the clock any more. Here's a link to the web
page
> documenting what I did with the clock
>
> http://www.seismicnet.com/wwvbsdr.html
>
> Regards,
> Larry Cochrane
> Redwood City, PSN
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Subject: Re: Atomic Time Source for data logging
From: Bobhelenmcclure@.......
Date: Sun, 23 Feb 2003 00:52:59 EST
My nearby seismic buddy and I have established a local area tripartite
network for the study of microseisms. We record for short periods
simultaneously at three sites, and require accurate timing of the three
records in order to calculate time differences of arrival. We use Dataq
RS-154 and RS-194 digitizers which have a digital input for registering time
marks on the records. We use WWVB controlled wall clocks for generating
minute marks.
My buddy uses large LCD RadioShack clocks, and photo-optically looks at the
lower right segment of the tens-of-seconds digit. This segment is black for
all digits except for the digit "2," so every minute it disappears at 20
seconds past the minute for 10 seconds. His pickup circuit has a logic high
output whenever the segment is black and low when it is absent. The Dataq
recorder will make a mark at either of the transitions. He uses the
high-to-low transitions, so gets minute marks 20 seconds past the minute.
I use an analog wall clock, brand name "Atomix," distributed by Cheney
Instruments. I removed the plastic face, glued a . 25-inch circle of
aluminum foil reflector to the sweep second hand, and replaced the face. The
pickoff is held in place by a rubber band and string, and is positioned on
the clock face to detect the second hand when it is at the even minute. The
pickoff circuitry is mounted in a wooden block, painted black. The light
source is a red LED and the detector is a phototransistor, coupled to a
medium-gain NPN transistor. There are some potential problems with this
scheme. For one thing, the clock goes through an adjustment procedure every
few hours to synchronize with WWVB. It starts running fast and then slows
down to fall into alignment with the radio signal. Except for the few
minutes when this is going on, the clock is very accurate. Another potential
problem is that the second hand does not simply jump from one second to the
next, but overshoots before settling down. The pickoff must be carefully
positioned to avoid sensing the bounce from second 59 and well as the dwell
at second zero. I purchased two of these clocks from HeartlandAmerica, and
one of them had too much bounce to be useful.
We have tested both marking schemes at the same site on a single digitizer,
and have determined that there is no detectable differences in our timing
(except for the fixed 20-second offset.)
With analog wall clocks, it is also possible to generate one-second marks
by inductively picking up the clock's stepper motor's current pulse.
If anyone is interested in trying the above schemes, I will be happy to
give further details.
Bob McClure
My nearby seismic buddy and I have established=20=
a local area tripartite network for the study of microseisms. We recor=
d for short periods simultaneously at three sites, and require accurate timi=
ng of the three records in order to calculate time differences of arrival.&n=
bsp; We use Dataq RS-154 and RS-194 digitizers which have a digital input fo=
r registering time marks on the records. We use WWVB controlled wall c=
locks for generating minute marks.
My buddy uses large LCD RadioShack clocks, and photo-optically looks=20=
at the lower right segment of the tens-of-seconds digit. This segment=20=
is black for all digits except for the digit "2," so every minute it disappe=
ars at 20 seconds past the minute for 10 seconds. His pickup circuit h=
as a logic high output whenever the segment is black and low when it is abse=
nt. The Dataq recorder will make a mark at either of the transitions.&=
nbsp; He uses the high-to-low transitions, so gets minute marks 20 seconds p=
ast the minute.
I use an analog wall clock, brand name "Atomix," distributed by Chene=
y Instruments. I removed the plastic face, glued a . 25-inch circle of=
aluminum foil reflector to the sweep second hand, and replaced the face.&nb=
sp; The pickoff is held in place by a rubber band and string, and is positio=
ned on the clock face to detect the second hand when it is at the even minut=
e. The pickoff circuitry is mounted in a wooden block, painted black.&=
nbsp; The light source is a red LED and the detector is a phototransistor, c=
oupled to a medium-gain NPN transistor. There are some potential probl=
ems with this scheme. For one thing, the clock goes through an adjustm=
ent procedure every few hours to synchronize with WWVB. It starts runn=
ing fast and then slows down to fall into alignment with the radio signal.&n=
bsp; Except for the few minutes when this is going on, the clock is very acc=
urate. Another potential problem is that the second hand does not simp=
ly jump from one second to the next, but overshoots before settling down.&nb=
sp; The pickoff must be carefully positioned to avoid sensing the bounce fro=
m second 59 and well as the dwell at second zero. I purchased two of t=
hese clocks from HeartlandAmerica, and one of them had too much bounce to be=
useful.
We have tested both marking schemes at the same site on a single digi=
tizer, and have determined that there is no detectable differences in our ti=
ming (except for the fixed 20-second offset.)
With analog wall clocks, it is also possible to generate one-second m=
arks by inductively picking up the clock's stepper motor's current pulse.
If anyone is interested in trying the above schemes, I will be happy=20=
to give further details.
Bob McClure
Subject: Re: Subject: Re: Atomic Time Source for data logging
From: "Jonathan Peakall" jpeakall@............
Date: Sun, 23 Feb 2003 06:29:04 -0800
Bob, All,
Following Bob's ideas and with his help, I made basically the same =
system. The only difference was I used an photogate of the style that is =
used in floppy drives, and painted the second hand white. Works like a =
champ and is cheap. I put the gate on an arm that pivots on the "hands =
holder", and clamps on the edge of the face for easy adjustment.
Later however, when I was trying to get the actual time and date from =
the unit, I realized how easy it was to pull a direct 1PPS from the =
unit. I then got rid of the photogate and used that to make marks via =
the DATAQ 194-RS. This is much better, no bounce. I eliminated the =
actual clock mechanism, and now the battery lasts forever. Mind you, it =
isn't very useful as a clock anymore! Bob, if you are interested in =
details let me know. It's very simple surgery.
The main reason for going to all the trouble I did for atomic time is I =
wanted to be able to make more than minute marks on my log, and I have a =
number of projects that can use an accurate time base. Since I will have =
at least 4 devices using the timebase, it was a reasonably economical =
solution as well, I have a total of less then US$100 into the atomic =
time broadcast system. A clock chip for all my projects would have been =
about the same or a little less, but then I don't have to use any =
buttons and I/O pins used (except one I/O pin) or use program space on =
time setting routines.
Another reason is the cheap clock I was using didn't link very often to =
WWVB. This is due to my poor reception. The module I am using now is =
much better.
Now all I have to do is weatherize my seismic sensor and get back to =
work on it. The school year is crazy for me, so I hope to get it all set =
up this summer, if I don't have to move.
Regards,
Jonathan
www.madlabs.info
----- Original Message -----=20
From: Bobhelenmcclure@..........
To: psn-l@.................
Sent: Saturday, February 22, 2003 9:52 PM
Subject: Subject: Re: Atomic Time Source for data logging
My nearby seismic buddy and I have established a local area =
tripartite network for the study of microseisms. We record for short =
periods simultaneously at three sites, and require accurate timing of =
the three records in order to calculate time differences of arrival. We =
use Dataq RS-154 and RS-194 digitizers which have a digital input for =
registering time marks on the records. We use WWVB controlled wall =
clocks for generating minute marks.
My buddy uses large LCD RadioShack clocks, and photo-optically looks =
at the lower right segment of the tens-of-seconds digit. This segment =
is black for all digits except for the digit "2," so every minute it =
disappears at 20 seconds past the minute for 10 seconds. His pickup =
circuit has a logic high output whenever the segment is black and low =
when it is absent. The Dataq recorder will make a mark at either of the =
transitions. He uses the high-to-low transitions, so gets minute marks =
20 seconds past the minute.
I use an analog wall clock, brand name "Atomix," distributed by =
Cheney Instruments. I removed the plastic face, glued a . 25-inch =
circle of aluminum foil reflector to the sweep second hand, and replaced =
the face. The pickoff is held in place by a rubber band and string, and =
is positioned on the clock face to detect the second hand when it is at =
the even minute. The pickoff circuitry is mounted in a wooden block, =
painted black. The light source is a red LED and the detector is a =
phototransistor, coupled to a medium-gain NPN transistor. There are =
some potential problems with this scheme. For one thing, the clock goes =
through an adjustment procedure every few hours to synchronize with =
WWVB. It starts running fast and then slows down to fall into alignment =
with the radio signal. Except for the few minutes when this is going =
on, the clock is very accurate. Another potential problem is that the =
second hand does not simply jump from one second to the next, but =
overshoots before settling down. The pickoff must be carefully =
positioned to avoid sensing the bounce from second 59 and well as the =
dwell at second zero. I purchased two of these clocks from =
HeartlandAmerica, and one of them had too much bounce to be useful.
We have tested both marking schemes at the same site on a single =
digitizer, and have determined that there is no detectable differences =
in our timing (except for the fixed 20-second offset.)
With analog wall clocks, it is also possible to generate one-second =
marks by inductively picking up the clock's stepper motor's current =
pulse.
If anyone is interested in trying the above schemes, I will be happy =
to give further details.
Bob McClure=20
Bob, All,
Following Bob's ideas and with his =
help, I made=20
basically the same system. The only difference was I used an photogate =
of the=20
style that is used in floppy drives, and painted the second hand white. =
Works=20
like a champ and is cheap. I put the gate on an arm that pivots on the =
"hands=20
holder", and clamps on the edge of the face for easy =
adjustment.
Later however, when I was =
trying to get=20
the actual time and date from the unit, I realized how easy it was to =
pull a=20
direct 1PPS from the unit. I then got rid of the photogate and used that =
to make=20
marks via the DATAQ 194-RS. This is much better, no bounce. I eliminated =
the=20
actual clock mechanism, and now the battery lasts forever. Mind you, it =
isn't=20
very useful as a clock anymore! Bob, if you are interested in details =
let me=20
know. It's very simple surgery.
The main reason for going to all the =
trouble I did=20
for atomic time is I wanted to be able to make more than minute marks on =
my log,=20
and I have a number of projects that can use an accurate time base. =
Since I will=20
have at least 4 devices using the timebase, it was a reasonably =
economical=20
solution as well, I have a total of less then US$100 into the atomic =
time=20
broadcast system. A clock chip for all my projects would have been about =
the=20
same or a little less, but then I don't have to use any buttons and =
I/O=20
pins used (except one I/O pin) or use program space on time =
setting=20
routines.
Another reason is the cheap clock I was =
using=20
didn't link very often to WWVB. This is due to my poor reception. The =
module I=20
am using now is much better.
Now all I have to do is weatherize my =
seismic=20
sensor and get back to work on it. The school year is crazy for me, so I =
hope to=20
get it all set up this summer, if I don't have to move.
Subject: Subject: Re: Atomic =
Time Source=20
for data logging
My nearby seismic buddy and I have =
established a=20
local area tripartite network for the study of microseisms. We =
record=20
for short periods simultaneously at three sites, and require accurate =
timing=20
of the three records in order to calculate time differences of =
arrival. =20
We use Dataq RS-154 and RS-194 digitizers which have a digital input =
for=20
registering time marks on the records. We use WWVB controlled =
wall=20
clocks for generating minute marks.
My buddy uses large =
LCD=20
RadioShack clocks, and photo-optically looks at the lower right =
segment of the=20
tens-of-seconds digit. This segment is black for all digits =
except for=20
the digit "2," so every minute it disappears at 20 seconds past the =
minute for=20
10 seconds. His pickup circuit has a logic high output whenever =
the=20
segment is black and low when it is absent. The Dataq recorder =
will make=20
a mark at either of the transitions. He uses the high-to-low=20
transitions, so gets minute marks 20 seconds past the =
minute.
I=20
use an analog wall clock, brand name "Atomix," distributed by Cheney=20
Instruments. I removed the plastic face, glued a . 25-inch =
circle of=20
aluminum foil reflector to the sweep second hand, and replaced the =
face. =20
The pickoff is held in place by a rubber band and string, and is =
positioned on=20
the clock face to detect the second hand when it is at the even =
minute. =20
The pickoff circuitry is mounted in a wooden block, painted =
black. The=20
light source is a red LED and the detector is a phototransistor, =
coupled to a=20
medium-gain NPN transistor. There are some potential problems =
with this=20
scheme. For one thing, the clock goes through an adjustment =
procedure=20
every few hours to synchronize with WWVB. It starts running fast =
and=20
then slows down to fall into alignment with the radio signal. =
Except for=20
the few minutes when this is going on, the clock is very =
accurate. =20
Another potential problem is that the second hand does not simply jump =
from=20
one second to the next, but overshoots before settling down. The =
pickoff=20
must be carefully positioned to avoid sensing the bounce from second =
59 and=20
well as the dwell at second zero. I purchased two of these =
clocks from=20
HeartlandAmerica, and one of them had too much bounce to be=20
useful.
We have tested both marking schemes at the same =
site on=20
a single digitizer, and have determined that there is no detectable=20
differences in our timing (except for the fixed 20-second=20
offset.)
With analog wall clocks, it is also possible to =
generate one-second marks by inductively picking up the clock's =
stepper=20
motor's current pulse.
If anyone is interested in trying =
the=20
above schemes, I will be happy to give further details.
Bob=20
McClure
Subject: Re: Atomic Time Source for data logging
From: "Jonathan Peakall" jpeakall@............
Date: Sun, 23 Feb 2003 06:51:55 -0800
Chris,
Thanks for all the info. I would like to try to see what my signal =
strength is with these various stations is. Maybe I can borrow a =
receiver and find out. My link to WWVB is still more dodgy than I would =
like. I am in northern California and not TOO far from WWVB, but I live =
in a "black hole" of RF. My fire dept. pager often doesn't go off at =
home, and I am pretty close to the transmitter. As soon as I get a mile =
down the road it is much better.
Jonathan
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Sent: Friday, February 21, 2003 5:45 PM
Subject: Re: Atomic Time Source for data logging
In a message dated 21/02/03, jpeakall@............ writes:=20
Neat looking units. Have you interfaced a micro with these? If so, =
what micro did you use? What format/baud rate does the data come in?
Hi Jonathan,=20
If you call up http://www.hkw-elektronik.de/pdf/fbw13010_dd.pdf =
you will get a description of the WWVB receiver. It can be configured to =
give +ve or -ve output pulses following the format of the WWVB signal, =
which are of 1 pulse per second, but different lengths. There is an AVC =
line which follows the signal strength and provides the zero signal =
level reference. Note that a crystal filter is used, which provides very =
narrow band reception. HKW also do a decoder chip which takes in the =
signal and gives out RS232. Note that WWVB, MSF, DCF and JJY are all =
different time formats. Two ferrite rod aerials are available, 60 mm or =
100 mm long. =20
Larry has a note on WWVB at =
http://www.seismicnet.com/wwvbsdr.html and has modified software to =
drive the card. Boulder give a time accuracy to within 0.1 milli second =
with a good receiver. The errors due to changes in radio signal path are =
generally much less that with WWV.=20
I do not know if these very narrow band receivers will work all =
over the US, but Boulder have increased the transmitter power to 50 KW. =
Maine is about 1900 m from Boulder, so it must be getting near the =
limit. I use DCF and it is very reliable, but I am only about 650 km =
from the transmitter ~400 m. Night time reception of DCF is quoted to =
3000 km ~1900 m and daytime reception to 2000 km, which I can confirm. I =
checked my receiver sensitivity and to stop it working, I had to put it =
in a tin box and close the lid. And there are places in my house where =
you cannot get FM or even good MW radio reception. These very long wave =
signals seem to bend around mountains fairly well. I suggest that you =
look up http://www.boulder.nist.gov/timefreq/ for a lot more useful =
information.=20
Regards,=20
Chris Chapman=20
Chris,
Thanks for all the info. I would like =
to try to see=20
what my signal strength is with these various stations is. Maybe =
I can=20
borrow a receiver and find out. My link to WWVB is still more dodgy than =
I would=20
like. I am in northern California and not TOO far from WWVB, but I live =
in a=20
"black hole" of RF. My fire dept. pager often doesn't go off at home, =
and I am=20
pretty close to the transmitter. As soon as I get a mile down the road =
it is=20
much better.
Neat looking units. Have you interfaced a micro with =
these? If=20
so, what micro did you use? What format/baud rate does the data come =
in?
Hi Jonathan,=20
If you call up http://www.hkw-=
elektronik.de/pdf/fbw13010_dd.pdf=20
you will get a description of the WWVB receiver. It can be configured =
to give=20
+ve or -ve output pulses following the format of the WWVB signal, =
which are of=20
1 pulse per second, but different lengths. There is an AVC line which =
follows=20
the signal strength and provides the zero signal level reference. Note =
that a=20
crystal filter is used, which provides very narrow band reception. HKW =
also do=20
a decoder chip which takes in the signal and gives out RS232. Note =
that WWVB,=20
MSF, DCF and JJY are all different time formats. Two ferrite rod =
aerials are=20
available, 60 mm or 100 mm long. =20
Larry has a note on WWVB =
at=20
http://www.seismicnet.com/wwvbsdr.html and has modified software to =
drive the=20
card. Boulder give a time accuracy to within 0.1 milli second with a =
good=20
receiver. The errors due to changes in radio signal path are generally =
much=20
less that with WWV.
I do =
not know=20
if these very narrow band receivers will work all over the US, but =
Boulder=20
have increased the transmitter power to 50 KW. Maine is about 1900 m =
from=20
Boulder, so it must be getting near the limit. I use DCF and it is =
very=20
reliable, but I am only about 650 km from the transmitter ~400 m. =
Night time=20
reception of DCF is quoted to 3000 km ~1900 m and daytime reception to =
2000=20
km, which I can confirm. I checked my receiver sensitivity and to stop =
it=20
working, I had to put it in a tin box and close the lid. And there are =
places=20
in my house where you cannot get FM or even good MW radio reception. =
These=20
very long wave signals seem to bend around mountains fairly well. I =
suggest=20
that you look up http://www.boulder.nist.gov/timefreq/ for a lot more =
useful=20
information.
Regards,=20
Chris Chapman=20
Subject: AD Converter Modification
From: Richard Diaz rdiaz@.........
Date: Sun, 23 Feb 2003 19:23:26 -0700
I am from Colorado School of Mines and currently am working on a
seismometer to be mass produced for general education classroom use.
We have been using the DATAQ instruments DI-194RS starter kit, but is
not really streamlined for what we need it for. I was thinking about
an AD converter that only has two input, and outputs to a USB port,
since it is becoming a mainstream method of PC input. I am not really
sure how to go about modifying and AD converter in such a manner. If
anyone has any insight, could you please assist?
Thanks
Richard Diaz
Colorado School of Mines
Engineering - Electrical Specialty
Computer Science
1807 W. Campus Rd
Golden, CO 80401
Home - (303)278-4157
Mobile - (303)522-4801
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: AD Converter Modification
From: "a.rodriguez" stuff@.................
Date: Mon, 24 Feb 2003 06:52:04 -0500
Hello Richard,
Serial to USB converters are in the mid $20.00 ands work quite well.
Just do a google with "usb serial converter" and you will see.
I agree that USB is becoming more and more common, but most computers
that are usually pressed into data logging service have one if not
more serial ports.
Sunday, February 23, 2003, 9:23:26 PM, you wrote:
RD> I am from Colorado School of Mines and currently am working on a
RD> seismometer to be mass produced for general education classroom use.
RD> We have been using the DATAQ instruments DI-194RS starter kit, but is
RD> not really streamlined for what we need it for. I was thinking about
RD> an AD converter that only has two input, and outputs to a USB port,
RD> since it is becoming a mainstream method of PC input. I am not really
RD> sure how to go about modifying and AD converter in such a manner. If
RD> anyone has any insight, could you please assist?
regards,
angel
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: AD Converter Modification
From: "David Saum" DSaum@............
Date: Tue, 25 Feb 2003 10:38:45 -0500
Richard,
To keep costs as low as possible
you might want to find a microprocessor
with onboard ADC and USB ports. I am
using a PIC14000 with onboard 16 bit
ADC ports, but it can only do a software
based standard serial I/O. There is a PIC16c77
that has onboard 12 bit ADC ports, plus a port
that can be used for software based USB, all for
about $5. See my web page for some PIC
programming links.
http://www.infiltec.com/seismo/#micro
Also see Jan Axelson's book "USB Complete".
http://www.amazon.com/exec/obidos/tg/detail/-/0965081958/
Unfortunately USB I/O is a lot more
complicated than serial.
Hope this helps,
Dave
http://www.infiltec.com/seismo/
> From: Richard Diaz
> Date: Sun, 23 Feb 2003 19:23:26 -0700
>
> I am from Colorado School of Mines and currently am working on a
> seismometer to be mass produced for general education classroom use.
> We have been using the DATAQ instruments DI-194RS starter kit, but is
> not really streamlined for what we need it for. I was thinking about
> an AD converter that only has two input, and outputs to a USB port,
> since it is becoming a mainstream method of PC input. I am not really
> sure how to go about modifying and AD converter in such a manner. If
> anyone has any insight, could you please assist?
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: AD Converter Modification
From: "Euro Atencio" eatencio@..........
Date: Tue, 25 Feb 2003 11:49:06 -0500
I haven't get the chance to talk to you lately, but I've being fliying like
a "Pilot", going from South America, Central America and Europe, for example
I was in Venezuela last week and came back on Friday and I will be fliying
to nite to London and will be back on Sat and then I will be in Baltimore
next week. But tell me how is it going? How are activities in SID? Is the
planet would split in two do to the fact on lot of quakes? jajaja! got you.
Best Regards;
Euro
----- Original Message -----
From: "David Saum"
To:
Sent: Tuesday, February 25, 2003 10:38 AM
Subject: Re: AD Converter Modification
> Richard,
>
> To keep costs as low as possible
> you might want to find a microprocessor
> with onboard ADC and USB ports. I am
> using a PIC14000 with onboard 16 bit
> ADC ports, but it can only do a software
> based standard serial I/O. There is a PIC16c77
> that has onboard 12 bit ADC ports, plus a port
> that can be used for software based USB, all for
> about $5. See my web page for some PIC
> programming links.
> http://www.infiltec.com/seismo/#micro
> Also see Jan Axelson's book "USB Complete".
> http://www.amazon.com/exec/obidos/tg/detail/-/0965081958/
> Unfortunately USB I/O is a lot more
> complicated than serial.
>
> Hope this helps,
>
> Dave
> http://www.infiltec.com/seismo/
>
> > From: Richard Diaz
> > Date: Sun, 23 Feb 2003 19:23:26 -0700
> >
> > I am from Colorado School of Mines and currently am working on a
> > seismometer to be mass produced for general education classroom use.
> > We have been using the DATAQ instruments DI-194RS starter kit, but is
> > not really streamlined for what we need it for. I was thinking about
> > an AD converter that only has two input, and outputs to a USB port,
> > since it is becoming a mainstream method of PC input. I am not really
> > sure how to go about modifying and AD converter in such a manner. If
> > anyone has any insight, could you please assist?
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: AD Converter Modification
From: Karl Cunningham karlc@..........
Date: Wed, 26 Feb 2003 13:21:19 -0800
Richard --
Check out the 1-wire devices. See
http://www.maxim-ic.com/quick_view2.cfm?qv_pk=2921&ln=
This is in the 1-wire family of devices that only use one wire (plus
ground) to communicate with another 1-wire device or a host comptuer. They
have adaptors for serial port and USB at the PC end. See
http://www.maxim-ic.com/quick_view2.cfm/qv_pk/2995
Unfortunately, this is not a plug-n-play solution. You'd have to do some
wiring and probably some software.
The 1-wire stuff looks like it might be useful in the future as the
technology matures. Here is an overview:
http://www.maxim-ic.com/1-Wire.cfm
Karl Cunningham
--On Sunday, February 23, 2003 7:23 PM -0700 Richard Diaz
wrote:
> I am from Colorado School of Mines and currently am working on a
> seismometer to be mass produced for general education classroom use. We
> have been using the DATAQ instruments DI-194RS starter kit, but is not
> really streamlined for what we need it for. I was thinking about an AD
> converter that only has two input, and outputs to a USB port, since it is
> becoming a mainstream method of PC input. I am not really sure how to go
> about modifying and AD converter in such a manner. If anyone has any
> insight, could you please assist?
>
>
> Thanks
>
>
> Richard Diaz
> Colorado School of Mines
> Engineering - Electrical Specialty
> Computer Science
>
> 1807 W. Campus Rd
> Golden, CO 80401
> Home - (303)278-4157
> Mobile - (303)522-4801
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with the body of
> the message (first line only): unsubscribe See
> http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Radiosky A-to-Ds
From: "David H. Youden" dyouden@.........
Date: Sun, 02 Mar 2003 06:08:49 -0500
All,
Has anyone out there tried to use the A/D converters documented on
radiosky.com? If so, do you have any comments on functionality, cost,
construction, etc?
I'm trying to help the group at Colorado School of Mines with their
affordable seismometer project, so your input will be highly valued.
Thanks in advance,
Dave...
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Digest from 03/02/2003 00:01:39
From: "Norman Davis" wb6shi@........
Date: Mon, 3 Mar 2003 11:31:43 -0800
contact Jim directly. He has been very helpful in the passed and has done
some quake stuff also....
Norm
----- Original Message -----
From:
To:
Sent: Monday, March 03, 2003 12:01 AM
Subject: Digest from 03/02/2003 00:01:39
>
> .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> | Message 1 |
> '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> Subject: Radiosky A-to-Ds
> From: "David H. Youden"
> Date: Sun, 02 Mar 2003 06:08:49 -0500
>
> All,
>
> Has anyone out there tried to use the A/D converters documented on
> radiosky.com? If so, do you have any comments on functionality, cost,
> construction, etc?
>
> I'm trying to help the group at Colorado School of Mines with their
> affordable seismometer project, so your input will be highly valued.
>
> Thanks in advance,
> Dave...
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-DIGEST-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: New WinQuake and WinPlotGPS releases
From: "Larry Cochrane" cochrane@..............
Date: Mon, 3 Mar 2003 20:29:02 -0800
Hi Everyone,
I have new releases of WinQuake and WinPlotGPS available on my web site here
http://www.seismicnet.com/wqdocs/wqbeta.html and
http://www.seismicnet.com/winplotgps/.
WinQuake;
The only new feature in this release is the ability to read MINISEED
volumes. I added this feature so I could look at event files from the IRIS
Bud system. See this link
http://www.iris.washington.edu/bud_stuff/dmc/bud_monitor.html for a starting
point to download MINISEED files from their system. The problem with
MINISEED files is they only contain the raw data. Information like sensor
location, sensor type etc are not part of the data file. When processing
MINISEED files, it is assumed you have the stationary information like
station latitude and longitude in a dataless SEED file (or some other
format) that can be used to fill in the missing data. When you open a
MINISEED file, WinQuake will try and find a dataless SEED file on the system
so it can use it to fill in the missing data. See the documentation at the
bottom of the beta release web page for more information.
WinPlotGPS;
The program can now act as a TCP/IP GPS data server or client. I added this
feature because I thought it would be "cool" to do it. I'm not sure how
practical this new feature is, but with it you can send the data from the
GPS receiver over the Internet (or local LAN) to another copy of WinPlotGPS.
See the WinPlotGPS documentation for more information. I hope to do the same
type of thing to my WinSDR datalogger. This way WinSDR users can remotely
monitor their system using a TCP/IP connection.
I also fixed a problem with the Reset GPS receiver command. Now when you use
this command with a ONCORE receiver (it has no effect on other GPS
receivers) the receiver will be reset back to the factory default settings.
Enjoy....
-Larry Cochrane
Redwood City, PSN
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: amp-filter board on ebay
From: BOB BARNS royb1@...........
Date: Tue, 04 Mar 2003 10:16:18 -0500
Hi gang,
An auction on ebay ending in 4 days offers:
Seismograph - Geophone Amplifier
Item # 2512765950
Looks good for either long period or geophone applications.
Bob Barns
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Digest from 03/03/2003 00:01:27
From: "Randall Pratt" rpratt@.............
Date: Tue, 4 Mar 2003 21:10:34 -0600
Dave,
I have used the original RadioSky AtoDMax circuit on my Lehman for about 3
years. I use the PSN preamp filter circuit with power hardwired from the PC
supply. I have modified EMON to collect data in PSN format files from the
Maxim converter. It all works quite well other than there is no stable time
reference. I've experimented with several programs such as Right Time and
they will give a fairly stable clock but I have not been able to get a
combination of stable time running with EMON. The date will not roll over
at best or the machine will lock at midnight. The same result has occurred
on 2 different PCs. If doing over I would power the system some other way
simply for convenience of changing computer and also for mobility as I have
loaned the system to the high school and a local college on several
occasions.
----- Original Message -----
From:
To:
Sent: Tuesday, March 04, 2003 2:00 AM
Subject: Digest from 03/03/2003 00:01:27
>
> .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> | Message 1 |
> '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> Subject: Re: Digest from 03/02/2003 00:01:39
> From: "Norman Davis"
> Date: Mon, 3 Mar 2003 11:31:43 -0800
>
> contact Jim directly. He has been very helpful in the passed and has done
> some quake stuff also....
>
> Norm
>
> ----- Original Message -----
> From:
> To:
> Sent: Monday, March 03, 2003 12:01 AM
> Subject: Digest from 03/02/2003 00:01:39
>
>
> >
> > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> > | Message 1 |
> > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> > Subject: Radiosky A-to-Ds
> > From: "David H. Youden"
> > Date: Sun, 02 Mar 2003 06:08:49 -0500
> >
> > All,
> >
> > Has anyone out there tried to use the A/D converters documented on
> > radiosky.com? If so, do you have any comments on functionality, cost,
> > construction, etc?
> >
> > I'm trying to help the group at Colorado School of Mines with their
> > affordable seismometer project, so your input will be highly valued.
> >
> > Thanks in advance,
> > Dave...
> >
> >
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-DIGEST-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
> >
>
>
>
>
> .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> | Message 2 |
> '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> Subject: New WinQuake and WinPlotGPS releases
> From: "Larry Cochrane"
> Date: Mon, 3 Mar 2003 20:29:02 -0800
>
> Hi Everyone,
>
> I have new releases of WinQuake and WinPlotGPS available on my web site
here
> http://www.seismicnet.com/wqdocs/wqbeta.html and
> http://www.seismicnet.com/winplotgps/.
>
> WinQuake;
> The only new feature in this release is the ability to read MINISEED
> volumes. I added this feature so I could look at event files from the IRIS
> Bud system. See this link
> http://www.iris.washington.edu/bud_stuff/dmc/bud_monitor.html for a
starting
> point to download MINISEED files from their system. The problem with
> MINISEED files is they only contain the raw data. Information like sensor
> location, sensor type etc are not part of the data file. When processing
> MINISEED files, it is assumed you have the stationary information like
> station latitude and longitude in a dataless SEED file (or some other
> format) that can be used to fill in the missing data. When you open a
> MINISEED file, WinQuake will try and find a dataless SEED file on the
system
> so it can use it to fill in the missing data. See the documentation at the
> bottom of the beta release web page for more information.
>
> WinPlotGPS;
> The program can now act as a TCP/IP GPS data server or client. I added
this
> feature because I thought it would be "cool" to do it. I'm not sure how
> practical this new feature is, but with it you can send the data from the
> GPS receiver over the Internet (or local LAN) to another copy of
WinPlotGPS.
> See the WinPlotGPS documentation for more information. I hope to do the
same
> type of thing to my WinSDR datalogger. This way WinSDR users can remotely
> monitor their system using a TCP/IP connection.
>
> I also fixed a problem with the Reset GPS receiver command. Now when you
use
> this command with a ONCORE receiver (it has no effect on other GPS
> receivers) the receiver will be reset back to the factory default
settings.
>
> Enjoy....
>
> -Larry Cochrane
> Redwood City, PSN
>
>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-DIGEST-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Digest from 03/03/2003 00:01:27
From: "David H. Youden" dyouden@.........
Date: Wed, 05 Mar 2003 05:54:44 -0500
Randall,
Thanks, I have purchased one of Jim's kits and will give it a try and
report my results.
Dave...
At 09:10 PM 3/4/03 -0600, you wrote:
>Dave,
>
>I have used the original RadioSky AtoDMax circuit on my Lehman for about 3
>years. I use the PSN preamp filter circuit with power hardwired from the PC
>supply. I have modified EMON to collect data in PSN format files from the
>Maxim converter. It all works quite well other than there is no stable time
>reference. I've experimented with several programs such as Right Time and
>they will give a fairly stable clock but I have not been able to get a
>combination of stable time running with EMON. The date will not roll over
>at best or the machine will lock at midnight. The same result has occurred
>on 2 different PCs. If doing over I would power the system some other way
>simply for convenience of changing computer and also for mobility as I have
>loaned the system to the high school and a local college on several
>occasions.
>
>----- Original Message -----
>From:
>To:
>Sent: Tuesday, March 04, 2003 2:00 AM
>Subject: Digest from 03/03/2003 00:01:27
>
>
> >
> > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> > | Message 1 |
> > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> > Subject: Re: Digest from 03/02/2003 00:01:39
> > From: "Norman Davis"
> > Date: Mon, 3 Mar 2003 11:31:43 -0800
> >
> > contact Jim directly. He has been very helpful in the passed and has done
> > some quake stuff also....
> >
> > Norm
> >
> > ----- Original Message -----
> > From:
> > To:
> > Sent: Monday, March 03, 2003 12:01 AM
> > Subject: Digest from 03/02/2003 00:01:39
> >
> >
> > >
> > > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> > > | Message 1 |
> > > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> > > Subject: Radiosky A-to-Ds
> > > From: "David H. Youden"
> > > Date: Sun, 02 Mar 2003 06:08:49 -0500
> > >
> > > All,
> > >
> > > Has anyone out there tried to use the A/D converters documented on
> > > radiosky.com? If so, do you have any comments on functionality, cost,
> > > construction, etc?
> > >
> > > I'm trying to help the group at Colorado School of Mines with their
> > > affordable seismometer project, so your input will be highly valued.
> > >
> > > Thanks in advance,
> > > Dave...
> > >
> > >
> > >
> > > __________________________________________________________
> > >
> > > Public Seismic Network Mailing List (PSN-L)
> > >
> > > To leave this list email PSN-L-DIGEST-REQUEST@.............. with
> > > the body of the message (first line only): unsubscribe
> > > See http://www.seismicnet.com/maillist.html for more information.
> > >
> >
> >
> >
> >
> > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> > | Message 2 |
> > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> > Subject: New WinQuake and WinPlotGPS releases
> > From: "Larry Cochrane"
> > Date: Mon, 3 Mar 2003 20:29:02 -0800
> >
> > Hi Everyone,
> >
> > I have new releases of WinQuake and WinPlotGPS available on my web site
>here
> > http://www.seismicnet.com/wqdocs/wqbeta.html and
> > http://www.seismicnet.com/winplotgps/.
> >
> > WinQuake;
> > The only new feature in this release is the ability to read MINISEED
> > volumes. I added this feature so I could look at event files from the IRIS
> > Bud system. See this link
> > http://www.iris.washington.edu/bud_stuff/dmc/bud_monitor.html for a
>starting
> > point to download MINISEED files from their system. The problem with
> > MINISEED files is they only contain the raw data. Information like sensor
> > location, sensor type etc are not part of the data file. When processing
> > MINISEED files, it is assumed you have the stationary information like
> > station latitude and longitude in a dataless SEED file (or some other
> > format) that can be used to fill in the missing data. When you open a
> > MINISEED file, WinQuake will try and find a dataless SEED file on the
>system
> > so it can use it to fill in the missing data. See the documentation at the
> > bottom of the beta release web page for more information.
> >
> > WinPlotGPS;
> > The program can now act as a TCP/IP GPS data server or client. I added
>this
> > feature because I thought it would be "cool" to do it. I'm not sure how
> > practical this new feature is, but with it you can send the data from the
> > GPS receiver over the Internet (or local LAN) to another copy of
>WinPlotGPS.
> > See the WinPlotGPS documentation for more information. I hope to do the
>same
> > type of thing to my WinSDR datalogger. This way WinSDR users can remotely
> > monitor their system using a TCP/IP connection.
> >
> > I also fixed a problem with the Reset GPS receiver command. Now when you
>use
> > this command with a ONCORE receiver (it has no effect on other GPS
> > receivers) the receiver will be reset back to the factory default
>settings.
> >
> > Enjoy....
> >
> > -Larry Cochrane
> > Redwood City, PSN
> >
> >
> >
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-DIGEST-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
> >
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Digest from 03/02/2003 00:01:39
From: "David H. Youden" dyouden@.........
Date: Wed, 05 Mar 2003 05:56:34 -0500
Norm,
Thanks for your reply, I have purchased one of Jim's kits and will see how
it works and report my experience.
Dave...
At 11:31 AM 3/3/03 -0800, you wrote:
>contact Jim directly. He has been very helpful in the passed and has done
>some quake stuff also....
>
>Norm
>
>----- Original Message -----
>From:
>To:
>Sent: Monday, March 03, 2003 12:01 AM
>Subject: Digest from 03/02/2003 00:01:39
>
>
> >
> > .------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
> > | Message 1 |
> > '------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
> > Subject: Radiosky A-to-Ds
> > From: "David H. Youden"
> > Date: Sun, 02 Mar 2003 06:08:49 -0500
> >
> > All,
> >
> > Has anyone out there tried to use the A/D converters documented on
> > radiosky.com? If so, do you have any comments on functionality, cost,
> > construction, etc?
> >
> > I'm trying to help the group at Colorado School of Mines with their
> > affordable seismometer project, so your input will be highly valued.
> >
> > Thanks in advance,
> > Dave...
> >
> >
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-DIGEST-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
> >
>
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Adjustment Help
From: "Karl Koth" karl@............
Date: Wed, 5 Mar 2003 18:13:44 -0700
Hello,
I have just built and setup a Lehman design seismometer. I built it for =
my school science fair, so keep in mind when replying that I am not in =
tune to all of the technical stuff. My questions have to do with =
adjusting the seismometer to record correctly.
Attached is a sample of the data that I am currently getting. I was =
wondering if I need to damp more or if I need to turn down the gain or =
adjust the offset. I am using Larry Cochrane's Amp/Filter board and his =
16 bit A/D converter board. I have also read about changing the period =
length, but I am not sure how to change it. Any help getting this data =
to look right would be appreciated.=20
thank you,
Karl Koth
Hello,
I have just built and setup a Lehman =
design=20
seismometer. I built it for my school science fair, so keep in mind when =
replying that I am not in tune to all of the technical stuff. My =
questions=20
have to do with adjusting the seismometer to record =
correctly.
Attached is a sample of the data that I =
am=20
currently getting. I was wondering if I need to damp more or if I need =
to turn=20
down the gain or adjust the offset. I am using Larry Cochrane's =
Amp/Filter board=20
and his 16 bit A/D converter board. I have also read about changing the =
period=20
length, but I am not sure how to change it. Any help getting this data =
to look=20
right would be appreciated.
thank you,
Karl Koth
Subject: Re: Adjustment Help
From: "Larry Cochrane" cochrane@..............
Date: Wed, 5 Mar 2003 20:59:02 -0800
Karl,
Attachments are not allowed on the PSN-L list, this is how viruses get =
passed around. If you have access to a web or ftp server you can place =
your file on that system and send us the URL. If you don't have access =
to a server, send me the file and I will place it on my system and send =
out a message to let members know the location of the file.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----=20
From: Karl Koth=20
To: PSN-L@.................
Sent: Wednesday, March 05, 2003 5:13 PM
Subject: Adjustment Help
Hello,
I have just built and setup a Lehman design seismometer. I built it =
for my school science fair, so keep in mind when replying that I am not =
in tune to all of the technical stuff. My questions have to do with =
adjusting the seismometer to record correctly.
Attached is a sample of the data that I am currently getting. I was =
wondering if I need to damp more or if I need to turn down the gain or =
adjust the offset. I am using Larry Cochrane's Amp/Filter board and his =
16 bit A/D converter board. I have also read about changing the period =
length, but I am not sure how to change it. Any help getting this data =
to look right would be appreciated.=20
thank you,
Karl Koth
Karl,
Attachments are not allowed on the =
PSN-L list, this=20
is how viruses get passed around. If you have access to a web or ftp =
server you=20
can place your file on that system and send us the URL. If you don't =
have access=20
to a server, send me the file and I will place it on my system and =
send out=20
a message to let members know the location of the =
file.
I have just built and setup a Lehman =
design=20
seismometer. I built it for my school science fair, so keep in mind =
when=20
replying that I am not in tune to all of the technical stuff. My=20
questions have to do with adjusting the seismometer to record=20
correctly.
Attached is a sample of the data that =
I am=20
currently getting. I was wondering if I need to damp more or if I need =
to turn=20
down the gain or adjust the offset. I am using Larry Cochrane's =
Amp/Filter=20
board and his 16 bit A/D converter board. I have also read about =
changing the=20
period length, but I am not sure how to change it. Any help getting =
this data=20
to look right would be appreciated.
thank you,
Karl =
Koth
Subject: Adjustment Help
From: "Karl Koth" karl@............
Date: Wed, 5 Mar 2003 22:10:59 -0700
I was informed that attachments are not allowed on the mailing list. =
Below is a link to the picture to refer to for my previous message.
http://www.bluearcticdesigns.com/~sandspider/example
thanks Karl Koth
I was informed that attachments are not =
allowed on=20
the mailing list. Below is a link to the picture to refer to for my =
previous=20
message.
Subject: Re: Adjustment Help
From: ChrisAtUpw@.......
Date: Thu, 6 Mar 2003 10:20:45 EST
In a message dated 06/03/03, karl@............ writes:
> I have just built and setup a Lehman design seismometer. I built it for my
> school science fair, so keep in mind when replying that I am not in tune to
> all of the technical stuff. My questions have to do with adjusting the
> seismometer to record correctly.
Hi Karl,
It would be a great help if you could put a few Webcam or better
pictures of the seismometer on the Website and some idea of the dimensions.
Otherwise, we can only give you the most general help. It is sometimes
possible to spot mistakes in construction, etc. this way and to make helpful
suggestions for improvements and adjustments.
> Attached is a sample of the data that I am currently getting. I was
> wondering if I need to damp more or if I need to turn down the gain or
> adjust the offset. I am using Larry Cochrane's Amp/Filter board and his 16
> bit A/D converter board. I have also read about changing the period length,
> but I am not sure how to change it. Any help getting this data to look
>
The data covers ~8,000 counts, or 1/8 of the total range, but there
seems to be no indication of the total time, or whether this was a local
seismic event, etc. We need to know what we are looking at! A very
underdamped pendulum can move quite a lot. If your trace is just enviromental
noise, you have either much too little damping, much too high a gain, a great
deal of local noise, or all three! Do you have a magnet mounted on the moving
arm?
You need to set the period first and then set the damping to match. If
the centre of mass to pivot is length L, the period P = 2 x Pi x Sqrt(L / (g
x SinA)), where A is the angle between the axis of rotation of the arm and
the vertical (may be less than 1 degree). You can adjust this by changing the
lengthways slope of the baseplate with an adjusting screw, or by adjusting
the position of the nozzle and the length of the top wire, if you have this
setup. Reduce or remove the damping, deflect the arm maybe 1/2" and time it's
oscillations. Try for the slower end of 12 to 20 seconds. You may find that
beyond some period, like 20 seconds, the arm becomes unstable or erratic in
it's balance position, so it needs to be set for a lower period. Having
adjusted the period, you replace the damping, displace the arm a small
fraction of an inch, release it and see what it does. If it returns to the
central position with hardly any overshoot, this is fine. If it only very
slowly returns to zero with no overshoot at all, it is overdamped. If it
swings through one or more oscillations, it is underdamped. It is quickest to
do this visually at first and when you get it nearly right, reduce the
amplifier gain and take a recording.
Hope that this is of some help,
Regards,
Chris Chapman
In a message dated 06/03/=
03, karl@............ writes:
I have just built and setup=
a Lehman design seismometer. I built it for my school science fair, so keep=
in mind when replying that I am not in tune to all of the technical stuff.=20=
My questions have to do with adjusting the seismometer to record correctly.<=
/FONT>
Hi Karl,
It would be a great help if you cou=
ld put a few Webcam or better pictures of the seismometer on the Website and=
some idea of the dimensions. Otherwise, we can only give you the most gener=
al help. It is sometimes possible to spot mistakes in construction, etc. thi=
s way and to make helpful suggestions for improvements and adjustments.
Attached is a sample of the=
data that I am currently getting. I was wondering if I need to damp more or=
if I need to turn down the gain or adjust the offset. I am using Larry Coch=
rane's Amp/Filter board and his 16 bit A/D converter board. I have also read=
about changing the period length, but I am not sure how to change it. Any h=
elp getting this data to look right would be appreciated.
The data covers ~8,000 counts, or 1=
/8 of the total range, but there seems to be no indication of the total time=
, or whether this was a local seismic event, etc. We need to know what we ar=
e looking at! A very underdamped pendulum can move quite a lot. If your trac=
e is just enviromental noise, you have either much too little damping, much=20=
too high a gain, a great deal of local noise, or all three! Do you have a ma=
gnet mounted on the moving arm?
You need to set the period first an=
d then set the damping to match. If the centre of mass to pivot is length L,=
the period P =3D 2 x Pi x Sqrt(L / (g x SinA)), where A is the angle betwee=
n the axis of rotation of the arm and the vertical (may be less than 1 degre=
e). You can adjust this by changing the lengthways slope of the baseplate wi=
th an adjusting screw, or by adjusting the position of the nozzle and the le=
ngth of the top wire, if you have this setup. Reduce or remove the damping,=20=
deflect the arm maybe 1/2" and time it's oscillations. Try for the slower en=
d of 12 to 20 seconds. You may find that beyond some period, like 20 seconds=
, the arm becomes unstable or erratic in it's balance position, so it needs=20=
to be set for a lower period. Having adjusted the period, you replace the da=
mping, displace the arm a small fraction of an inch, release it and see what=
it does. If it returns to the central position with hardly any overshoot, t=
his is fine. If it only very slowly returns to zero with no overshoot at all=
, it is overdamped. If it swings through one or more oscillations, it is und=
erdamped. It is quickest to do this visually at first and when you get it ne=
arly right, reduce the amplifier gain and take a recording.=20
Hope that this is of some help,
Regards,
Chris Chapman
Subject: Fw: Folded Pendulum Seismometer
From: "Larry Cochrane" cochrane@..............
Date: Thu, 6 Mar 2003 16:27:10 -0800
Hi Everyone,
I received this email from Dave Youden regarding a Folded Pendulum
Seismometer design. Dave is on the PSN-L list. I've placed Dave's Lehman
photo on my system here http://www.seismicnet.com/photos/lehman1a.jpg and
his write-up here
http://www.seismicnet.com/photos/Folded_Pendulum_seismometer.doc. It's in
Microsoft Word format.
I have one question for Dave. What material was used as a base and support
for your Lehman sensor?
Regards,
Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "David H. Youden"
To: "Larry Cochrane"
Sent: Thursday, March 06, 2003 6:18 AM
Subject: Folded Pendulum Seismometer
> Larry,
>
> Please allow me to introduce myself.
>
> My name is Dave Youden. I am an applied research engineer employed by
> Eastman Kodak Company where I work on the design of precision production
> equipment. I am also a member of the faculty of the Mechanical and
> Aerospace Engineering Department of North Carolina State University. I
live
> in Clayton, NC, a small, but growing community Southeast of Raleigh, NC.
>
> I have had a life long interest in earth sciences, and several years ago I
> built my first seismometer (See photo Lehman.jpg). A year later I built a
> small S-G instrument the performance of which was disappointing, probably
> because the 100 mm pendulum was simply too small and was subject to
> disturbance by air currrents.
>
> As a replacement for the S-G instrument I have designed and constructed a
> folded pendulum instrument which may be of interest to members of the PSN
> group. Please take a look at the file Folded Pedulum Seismometer.doc and
if
> you think that this would be of any interest to the group, you are free to
> post it if you wish, as I do not have access to a web server.
>
> I am a member of the PSN-L mailing list, and I will be more than happy to
> answer any question that you, or anyone else may have about this
instrument.
>
> The reason that I am sending this to you is that, while web surfing the
> other day, I ran across John Lahr's web site where I saw a picture of a
> folded pendulum experiment that he has constructed. I contacted John, and
> since then have been providing information to a group of students at The
> Colorado School of Mines, who are trying to design a low-cost seismometer
> suitable for public school use. Until I contacted John I really had no
idea
> that what I have built might be of interest to anyone else.
>
> Dave...
>
> David H. Youden
> dyouden@.........
>
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Adjustment Help
From: "Larry Cochrane" cochrane@..............
Date: Thu, 6 Mar 2003 16:32:53 -0800
Karl,
It would help if you place an event file on the Web so we can look at =
the data more closely. You definitely have too much gain or your sensor =
is under damped or you have a nasty resonance somewhere.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----=20
From: Karl Koth=20
To: PSN-L@.................
Sent: Wednesday, March 05, 2003 9:10 PM
Subject: Adjustment Help
I was informed that attachments are not allowed on the mailing list. =
Below is a link to the picture to refer to for my previous message.
http://www.bluearcticdesigns.com/~sandspider/example
thanks Karl Koth
Karl,
It would help if you place an event =
file on the Web=20
so we can look at the data more closely. You definitely have too much =
gain or=20
your sensor is under damped or you have a nasty resonance=20
somewhere.
Subject: Re: New WinQuake and WinPlotGPS releases
From: Karl Cunningham karlc@..........
Date: Thu, 06 Mar 2003 20:31:46 -0800
Larry --
Is there a possibility of getting SDRservr to interface with WinSDR over
TCP/IP rather than the serial link? I know SDRservr runs in DOS, which is
not very TCP/IP friendly. Just thought I'd ask.
Karl Cunningham
--On Monday, March 03, 2003 20:29 -0800 Larry Cochrane
wrote:
> WinPlotGPS;
> The program can now act as a TCP/IP GPS data server or client. I added
> this feature because I thought it would be "cool" to do it. I'm not sure
> how practical this new feature is, but with it you can send the data from
> the GPS receiver over the Internet (or local LAN) to another copy of
> WinPlotGPS. See the WinPlotGPS documentation for more information. I hope
> to do the same type of thing to my WinSDR datalogger. This way WinSDR
> users can remotely monitor their system using a TCP/IP connection.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake and WinPlotGPS releases
From: "Larry Cochrane" cochrane@..............
Date: Fri, 7 Mar 2003 02:11:16 -0800
Hi Karl,
I tried this a few years ago. The DOS TCP/IP stack (Wattcp) disabled
interrupts for too long of a time. This caused SDR to loose time every time
a packet was sent.
Yesterday I was able to get one WinSDR system to send data to another WinSDR
system using TCP/IP. It still needs a lot of work, so it will be a week or
so before I have a new release ready for beta testing.
Regards,
Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Karl Cunningham"
To:
Sent: Thursday, March 06, 2003 8:31 PM
Subject: Re: New WinQuake and WinPlotGPS releases
> Larry --
>
> Is there a possibility of getting SDRservr to interface with WinSDR over
> TCP/IP rather than the serial link? I know SDRservr runs in DOS, which is
> not very TCP/IP friendly. Just thought I'd ask.
>
> Karl Cunningham
>
>
>
> --On Monday, March 03, 2003 20:29 -0800 Larry Cochrane
> wrote:
>
> > WinPlotGPS;
> > The program can now act as a TCP/IP GPS data server or client. I added
> > this feature because I thought it would be "cool" to do it. I'm not sure
> > how practical this new feature is, but with it you can send the data
from
> > the GPS receiver over the Internet (or local LAN) to another copy of
> > WinPlotGPS. See the WinPlotGPS documentation for more information. I
hope
> > to do the same type of thing to my WinSDR datalogger. This way WinSDR
> > users can remotely monitor their system using a TCP/IP connection.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Fw: Folded Pendulum Seismometer
From: "David H. Youden" dyouden@.........
Date: Fri, 07 Mar 2003 05:53:32 -0500
Larry,
I used plain old concrete. Mortar mix works best. Line the mould with
plastic sheeting for a smooth surface finish, and let it age for a week
before you try to do anything with it. It worked for me - on the second try.
At 04:27 PM 3/6/03 -0800, you wrote:
>Hi Everyone,
>
>I received this email from Dave Youden regarding a Folded Pendulum
>Seismometer design. Dave is on the PSN-L list. I've placed Dave's Lehman
>photo on my system here http://www.seismicnet.com/photos/lehman1a.jpg and
>his write-up here
>http://www.seismicnet.com/photos/Folded_Pendulum_seismometer.doc. It's in
>Microsoft Word format.
>
>I have one question for Dave. What material was used as a base and support
>for your Lehman sensor?
>
>Regards,
>Larry Cochrane
>Redwood City, PSN
>
>----- Original Message -----
>From: "David H. Youden"
>To: "Larry Cochrane"
>Sent: Thursday, March 06, 2003 6:18 AM
>Subject: Folded Pendulum Seismometer
>
>
> > Larry,
> >
> > Please allow me to introduce myself.
> >
> > My name is Dave Youden. I am an applied research engineer employed by
> > Eastman Kodak Company where I work on the design of precision production
> > equipment. I am also a member of the faculty of the Mechanical and
> > Aerospace Engineering Department of North Carolina State University. I
>live
> > in Clayton, NC, a small, but growing community Southeast of Raleigh, NC.
> >
> > I have had a life long interest in earth sciences, and several years ago I
> > built my first seismometer (See photo Lehman.jpg). A year later I built a
> > small S-G instrument the performance of which was disappointing, probably
> > because the 100 mm pendulum was simply too small and was subject to
> > disturbance by air currrents.
> >
> > As a replacement for the S-G instrument I have designed and constructed a
> > folded pendulum instrument which may be of interest to members of the PSN
> > group. Please take a look at the file Folded Pedulum Seismometer.doc and
>if
> > you think that this would be of any interest to the group, you are free to
> > post it if you wish, as I do not have access to a web server.
> >
> > I am a member of the PSN-L mailing list, and I will be more than happy to
> > answer any question that you, or anyone else may have about this
>instrument.
> >
> > The reason that I am sending this to you is that, while web surfing the
> > other day, I ran across John Lahr's web site where I saw a picture of a
> > folded pendulum experiment that he has constructed. I contacted John, and
> > since then have been providing information to a group of students at The
> > Colorado School of Mines, who are trying to design a low-cost seismometer
> > suitable for public school use. Until I contacted John I really had no
>idea
> > that what I have built might be of interest to anyone else.
> >
> > Dave...
> >
> > David H. Youden
> > dyouden@.........
> >
> >
>
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Reinforced concrete base for Lehman instrument
From: beezaur beezaur@..........
Date: Fri, 07 Mar 2003 11:43:03 -0800
Hello,
I am preparing to build a Lehman type seismograph and was wondering
about materials for the base. I am considering a slab of reinforced
concrete (R/C) about 20" by 40" max, but coffin-shaped, say 3-4" thick
and ~120 lbs @ 150 pcf. This is similar to the stuff parking garage
floors are made of. It is a very stable material and can be cast to
include mounting points for various hardware.
I have read about the unreinforced recipee 1:1 sand:cement for piers,
but this does not give the bending strength required for my slab. I am
thinking of a more conventional mix using ~1:2:3 cement:sand:pea gravel
and a lot of small reinforcement (#3 bar or welded wire fabric). If I
vibrate it well, I should be able to avoid air pockets.
My main concern is thermally induced noise from reinforcement
expanding/contracting differently than concrete.
Has anyone done or heard about this? Do you think it would produce
internal noise?
Regards,
Scott P
--
A day without math is like a day without sunshine.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Reinforced concrete base for Lehman instrument
From: ChrisAtUpw@.......
Date: Sat, 8 Mar 2003 00:42:18 EST
In a message dated 07/03/03, beezaur@.......... writes:
> I have read about the unreinforced recipe 1:1 sand: cement for piers, but
> this does not give the bending strength required for my slab. I am
> thinking of a more conventional mix using ~1:2:3 cement:sand:pea gravel and
> a lot of small reinforcement (#3 bar or welded wire fabric). If I vibrate
> it well, I should be able to avoid air pockets.
>
> My main concern is thermally induced noise from reinforcement
> expanding/contracting differently than concrete.
>
> Has anyone done or heard about this? Do you think it would produce
> internal noise?
Dear Scott,
If I remember correctly, there was a note by Sean way back saying that
gravel was undesirable and re-bar was a definite no-no. I understand that
both can generate noise, with moisture and with temperature changes. I would
be most surprised if 1:1 sand and cement was not strong enough in practice,
but I would leave it covered in it's mould for a week. You can expect it to
take a month to fully cure. Concrete can then be dried out and given a coat
of something like pool paint to seal it and to reduce any metal to concrete
corrosion and any moisture changes.
Have you considered making a T base frame out of say 1.5" black steel
angle? 1 cross bar at the top and bottom and two long parallels for the II in
the T. Make the vertical hoop and cross bar out of the same material. You can
bolt and epoxy the joints, or alternatively arc weld them.
Regards,
Chris Chapman
In a message dated 07/03/=
03, beezaur@.......... writes:
I have read about the unrei=
nforced recipe 1:1 sand: cement for piers, but this does not give the bendin=
g strength required for my slab. I am thinking of a more conventional=20=
mix using ~1:2:3 cement:sand:pea gravel and a lot of small reinforcement (#3=
bar or welded wire fabric). If I vibrate it well, I should be able to=
avoid air pockets.
My main concern is thermally induced noise from reinforcement=20
expanding/contracting differently than concrete.
Has anyone done or heard about this? Do you think it would produce=
=20
internal noise?
Dear Scott,
If I remember correctly, there was=20=
a note by Sean way back saying that gravel was undesirable and re-bar was a=20=
definite no-no. I understand that both can generate noise, with moisture and=
with temperature changes. I would be most surprised if 1:1 sand and cement=20=
was not strong enough in practice, but I would leave it covered in it's moul=
d for a week. You can expect it to take a month to fully cure. Concrete can=20=
then be dried out and given a coat of something like pool paint to seal it a=
nd to reduce any metal to concrete corrosion and any moisture changes.
Have you considered making a T base=
frame out of say 1.5" black steel angle? 1 cross bar at the top and bottom=20=
and two long parallels for the II in the T. Make the vertical hoop and cross=
bar out of the same material. You can bolt and epoxy the joints, or alterna=
tively arc weld them.
Regards,
Chris Chapman
Subject: Re: Reinforced concrete base for Lehman instrument
From: "David H. Youden" dyouden@.........
Date: Sat, 08 Mar 2003 06:03:15 -0500
All,
I did not use reinforcing in the base of my instrument, and I did use a=20
sand mix of concrete. I also let it sit in the mould for a week, and it was=
=20
well over a month before the instrument was complete. I cannot say that I=20
have seen any noise that I can attribute to the use of this construction=20
technique. For the record, my base is about three feet long, 8 inches wide,=
=20
and about 6 inches high. It is shaped like a "U" in cross section to reduce=
=20
weight, and to minimize the cross section thickness. The column is also=20
similarly shaped with the back side hollowed out. The two pieces together=
=20
weight 80 or 90 pounds. It was a real effort to get the assembly off of the=
=20
workbench and down onto the floor.
The instrument lives in a temperature controlled enclosure at about =B10.5=
=B0F.=20
I consider this necessary to avoid thermal effects particularly because the=
=20
thing is set up in a corner of my garage which, although attached to the=20
house, is not heated.
Dave...
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake and WinPlotGPS releases
From: Karl Cunningham karlc@..........
Date: Sat, 08 Mar 2003 07:19:15 -0800
Hi Larry --
One of my thoughts is to set up two Linux boxes, one of which would convert
serial to TCP/IP and the other TCP/IP to serial. The first would sit next
to the SDRservr machine and the second next to the WinSDR machine. This
would allow the communication to go over TCP/IP (ethernet) instead of the
serial line. The goal is to take advantage of ethernet (or wireless) and
all its advantages over serial.
If you don't mind sharing... are you using a packet-based exchange or
streaming between the two WinSDR systems?
Karl
--On Friday, March 07, 2003 02:11 -0800 Larry Cochrane
wrote:
> Hi Karl,
>
> I tried this a few years ago. The DOS TCP/IP stack (Wattcp) disabled
> interrupts for too long of a time. This caused SDR to loose time every
> time a packet was sent.
>
> Yesterday I was able to get one WinSDR system to send data to another
> WinSDR system using TCP/IP. It still needs a lot of work, so it will be a
> week or so before I have a new release ready for beta testing.
>
> Regards,
> Larry Cochrane
> Redwood City, PSN
>
> ----- Original Message -----
> From: "Karl Cunningham"
> To:
> Sent: Thursday, March 06, 2003 8:31 PM
> Subject: Re: New WinQuake and WinPlotGPS releases
>
>
>> Larry --
>>
>> Is there a possibility of getting SDRservr to interface with WinSDR over
>> TCP/IP rather than the serial link? I know SDRservr runs in DOS, which
>> is not very TCP/IP friendly. Just thought I'd ask.
>>
>> Karl Cunningham
>>
>>
>>
>> --On Monday, March 03, 2003 20:29 -0800 Larry Cochrane
>> wrote:
>>
>> > WinPlotGPS;
>> > The program can now act as a TCP/IP GPS data server or client. I added
>> > this feature because I thought it would be "cool" to do it. I'm not
>> > sure how practical this new feature is, but with it you can send the
>> > data
> from
>> > the GPS receiver over the Internet (or local LAN) to another copy of
>> > WinPlotGPS. See the WinPlotGPS documentation for more information. I
> hope
>> > to do the same type of thing to my WinSDR datalogger. This way WinSDR
>> > users can remotely monitor their system using a TCP/IP connection.
>>
>> __________________________________________________________
>>
>> Public Seismic Network Mailing List (PSN-L)
>>
>> To leave this list email PSN-L-REQUEST@.............. with
>> the body of the message (first line only): unsubscribe
>> See http://www.seismicnet.com/maillist.html for more information.
>>
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Fw: Folded Pendulum Seismometer
From: ChrisAtUpw@.......
Date: Sat, 8 Mar 2003 11:15:50 EST
In a message dated 07/03/03, cochrane@.............. writes:
> http://www.seismicnet.com/photos/Folded_Pendulum_seismometer.doc
Dear Dave Youden,
The folded pendulum seismometer looks very interesting indeed.
Do you have the Australian references for this please?
Do you have the circuit diagram of the electronics, please?
Do you have information on the setup and performance, please?
Can you give further details of the aquarium cement that you used,
please?
Regards,
Chris Chapman
In a message dated 07/03/=
03, cochrane@.............. writes:
The folded pendulum seismometer loo=
ks very interesting indeed.=20
Do you have the Australian referenc=
es for this please?=20
Do you have the circuit diagram of=20=
the electronics, please?
Do you have information on the setu=
p and performance, please?=20
Can you give further details of the=
aquarium cement that you used, please?
Regards,
Chris Chapman
Subject: Re: Reinforced concrete base for Lehman instrument
From: beezaur beezaur@..........
Date: Sat, 08 Mar 2003 10:53:59 -0800
> temperature changes. I would be most surprised if 1:1 sand and cement
> was not strong enough in practice, . . .
>
> Have you considered making a T base frame out of say 1.5" black
> steel angle? . . .
> Regards,
>
> Chris Chapman
Chris,
Thank you.
I think you are right about the grout mix being strong on its own. It
isn't a trick to get regular concrete to 6000 psi compressive strength
(garden variety being 2000-3000 psi), and in fact the stone is what
usually breaks first in the really high strength stuff. I still worry
about brittleness - this device will have to survive a couple of moves
in the next few years. It would be interesting to see if my school will
test a cylinder or three before I graduate. How much water is typically
used?
Since rebar is a problem in concrete for the base, I assume I don't have
to ask about pouring the pier over 8 ft R/C pilings to better couple
with more stable ground at depth. It sounds to me like the soil/piling
interface would have the same noise problems as rebar/concrete. But
please correct me if that technique has proven reliable.
Steel or aluminum is "plan B" for the base of the instrument. The
support for the boom will be a metal tripod, bolted to the base. I
would like to keep the natural (resonant) frequency of that structure
very high, kHz if possible. I want to put my pickup and damping
hardware on the same base as the boom, hence the 40 in length. I hadn't
expected a "T" to get me there, but the design you describe may well be
stiff enough, especially with channel or square structural tubing.
Another thought: has anyone considered using carbon arrow shafts or
kevlar/spectra bowstring for boom components? They are pretty cheap
now, and their strength-to-weight ratios give them very good vibration
characteristics, and some bowstring absolutely does not creep.
Scott
--
A day without math is like a day without sunshine.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: link interes
From: "Centro de Operaciones" coecruzroja@................
Date: Sat, 8 Mar 2003 13:13:14 -0600
http://www.sciencecourseware.com/
best regard
___________________________________________________________________________
¿Ya probaste la Doble Velocidad? Con Navegante Doble Velocidad navegas al doble de la velocidad tradicional, y puedes hacer y recibir llamadas mientras estás conectado.
www.navegante.com.sv
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Reinforced concrete base for Lehman instrument
From: ChrisAtUpw@.......
Date: Sat, 8 Mar 2003 17:21:59 EST
In a message dated 08/03/03, beezaur@.......... writes:
> > temperature changes. I would be most surprised if 1:1 sand and cement
> > was not strong enough in practice, . . .
> > Have you considered making a T base frame out of say 1.5" black
> > steel angle? . . .
> > Regards,
> > Chris Chapman
>
> Chris,
>
> Thank you.
>
> I think you are right about the grout mix being strong on its own. It isn't
> a trick to get regular concrete to 6000 psi compressive strength (garden
> variety being 2000-3000 psi), and in fact the stone is what usually breaks
> first in the really high strength stuff. I still worry about brittleness -
> this device will have to survive a couple of moves in the next few years.
>
Unless you drop it or hit it with a hammer, I would not expect
brittleness to be a serious problem. I don't know about the water. It needs
to be saturated. I used an eccentric dowel on an electric drill to agitate
the mix and get the air out. It has a surface which is just liquid.
> Since rebar is a problem in concrete for the base, I assume I don't have to
> ask about pouring the pier over 8 ft R/C pilings to better couple with more
> stable ground at depth. It sounds to me like the soil/piling interface
> would have the same noise problems as rebar/concrete. But please correct
>
I do not know. The moisture variations could be considerable, but the
temperature variations are likely to be small. You also have tilt to
consider. This may be a limiting factor in the period you can use. I would
place a plinth on the earth / subsoil clear of any piles.
> Steel or aluminum is "plan B" for the base of the instrument. The support
> for the boom will be a metal tripod, bolted to the base. I would like to
> keep the natural (resonant) frequency of that structure very high, kHz if
> possible. I want to put my pickup and damping hardware on the same base as
> the boom, hence the 40 in length. I hadn't expected a "T" to get me there,
> but the design you describe may well be stiff enough, especially with
>
I suggest that you stick to steel. It is much more rigid. A completely
rectangular design is the easiest to construct. A simple design with the
least problems is more likely to get built! You can fit 6 to 8" lengths of
flat plate between the horizontal and vertical parallels to greatly increase
the rigidity and provide a pan for mounting sensors or damping devices. You
could use 1" L to brace the top of the U hoop to the end of the T arm. Could
one of the drive on steel ramps sold for car / truck maintenance be converted
- they come ready welded? Just a wild idea!
> Another thought: has anyone considered using carbon arrow shafts or kevlar /
> spectra bowstring for boom components? They are pretty cheap now, and their
> strength-to-weight ratios give them very good vibration characteristics,
> and some bowstring absolutely does not creep.
Carbon could be OK, but how do you plan to make the fittings? Metal is
easier to fabricate and fit. You can easily get nickel plated piano wire down
to 8 thou. from a music shop, it does not have any 'bending' memory and it
works just fine. See http://www.daddario.com/ Suggest that you forget kevlar
or other plastics. A ball bearing in the end of the arm gives an excellent
bottom suspension up against a stainless steel razor blade glued flat onto
the crossbar.
Regards,
Chris Chapman
In a message dated 08/03/=
03, beezaur@.......... writes:
> temperature changes. I=
would be most surprised if 1:1 sand and cement=20
> was not strong enough in practice, . . .
> Have you considered making a T=20=
base frame out of say 1.5" black=20
> steel angle? . . .
> Regards,
> Chris Chapman
Chris,
Thank you.
I think you are right about the grout mix being strong on its own. It is=
n't a trick to get regular concrete to 6000 psi compressive strength (garden=
variety being 2000-3000 psi), and in fact the stone is what usually breaks=20=
first in the really high strength stuff. I still worry about brittlene=
ss - this device will have to survive a couple of moves in the next few year=
s. How much water is typically used?
Unless you drop it or hit it with a=
hammer, I would not expect brittleness to be a serious problem. I don't kno=
w about the water. It needs to be saturated. I used an eccentric dowel on an=
electric drill to agitate the mix and get the air out. It has a surface whi=
ch is just liquid.
Since rebar is a problem in=
concrete for the base, I assume I don't have to ask about pouring the pier=20=
over 8 ft R/C pilings to better couple with more stable ground at depth. &nb=
sp;It sounds to me like the soil/piling interface would have the same noise=20=
problems as rebar/concrete. But please correct me if that technique ha=
s proven reliable.
I do not know. The moisture variati=
ons could be considerable, but the temperature variations are likely to be s=
mall. You also have tilt to consider. This may be a limiting factor in the p=
eriod you can use. I would place a plinth on the earth / subsoil clear of an=
y piles.
Steel or aluminum is "plan=20=
B" for the base of the instrument. The support for the boom will be a metal=20=
tripod, bolted to the base. I would like to keep the natural (resonant) freq=
uency of that structure very high, kHz if possible. I want to put my pickup=20=
and damping hardware on the same base as the boom, hence the 40 in length. I=
hadn't expected a "T" to get me there, but the design you describe may well=
be stiff enough, especially with channel or square structural tubing.
I suggest that you stick to steel.=20=
It is much more rigid. A completely rectangular design is the easiest=20=
to construct. A simple design with the least problems is more likely to get=20=
built! You can fit 6 to 8" lengths of flat plate between the horizontal and=20=
vertical parallels to greatly increase the rigidity and provide a pan for mo=
unting sensors or damping devices. You could use 1" L to brace the top of th=
e U hoop to the end of the T arm. Could one of the drive on steel ramps sold=
for car / truck maintenance be converted - they come ready welded? Just a w=
ild idea!
Another thought: has anyone=
considered using carbon arrow shafts or kevlar / spectra bowstring for boom=
components? They are pretty cheap now, and their strength-to-weight ratios=20=
give them very good vibration characteristics, and some bowstring absolutely=
does not creep.
Carbon could be OK, but how do you=20=
plan to make the fittings? Metal is easier to fabricate and fit. You can eas=
ily get nickel plated piano wire down to 8 thou. from a music shop, it does=20=
not have any 'bending' memory and it works just fine. See http://www.daddari=
o.com/ Suggest that you forget kevlar or other plastics. A ball bearing in t=
he end of the arm gives an excellent bottom suspension up against a stainles=
s steel razor blade glued flat onto the crossbar.
Regards,
Chris Chapman
Subject: Re: New WinQuake and WinPlotGPS releases
From: "Larry Cochrane" cochrane@..............
Date: Sat, 8 Mar 2003 17:48:08 -0800
Karl,
I am using TCP/IP packets not UDP streaming between WinSDR systems. This is
also that case with WinPlotGPS.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Karl Cunningham"
To:
Sent: Saturday, March 08, 2003 7:19 AM
Subject: Re: New WinQuake and WinPlotGPS releases
> Hi Larry --
>
> One of my thoughts is to set up two Linux boxes, one of which would
convert
> serial to TCP/IP and the other TCP/IP to serial. The first would sit next
> to the SDRservr machine and the second next to the WinSDR machine. This
> would allow the communication to go over TCP/IP (ethernet) instead of the
> serial line. The goal is to take advantage of ethernet (or wireless) and
> all its advantages over serial.
>
> If you don't mind sharing... are you using a packet-based exchange or
> streaming between the two WinSDR systems?
>
> Karl
>
>
> --On Friday, March 07, 2003 02:11 -0800 Larry Cochrane
> wrote:
>
> > Hi Karl,
> >
> > I tried this a few years ago. The DOS TCP/IP stack (Wattcp) disabled
> > interrupts for too long of a time. This caused SDR to loose time every
> > time a packet was sent.
> >
> > Yesterday I was able to get one WinSDR system to send data to another
> > WinSDR system using TCP/IP. It still needs a lot of work, so it will be
a
> > week or so before I have a new release ready for beta testing.
> >
> > Regards,
> > Larry Cochrane
> > Redwood City, PSN
> >
> > ----- Original Message -----
> > From: "Karl Cunningham"
> > To:
> > Sent: Thursday, March 06, 2003 8:31 PM
> > Subject: Re: New WinQuake and WinPlotGPS releases
> >
> >
> >> Larry --
> >>
> >> Is there a possibility of getting SDRservr to interface with WinSDR
over
> >> TCP/IP rather than the serial link? I know SDRservr runs in DOS, which
> >> is not very TCP/IP friendly. Just thought I'd ask.
> >>
> >> Karl Cunningham
> >>
> >>
> >>
> >> --On Monday, March 03, 2003 20:29 -0800 Larry Cochrane
> >> wrote:
> >>
> >> > WinPlotGPS;
> >> > The program can now act as a TCP/IP GPS data server or client. I
added
> >> > this feature because I thought it would be "cool" to do it. I'm not
> >> > sure how practical this new feature is, but with it you can send the
> >> > data
> > from
> >> > the GPS receiver over the Internet (or local LAN) to another copy of
> >> > WinPlotGPS. See the WinPlotGPS documentation for more information. I
> > hope
> >> > to do the same type of thing to my WinSDR datalogger. This way WinSDR
> >> > users can remotely monitor their system using a TCP/IP connection.
> >>
> >> __________________________________________________________
> >>
> >> Public Seismic Network Mailing List (PSN-L)
> >>
> >> To leave this list email PSN-L-REQUEST@.............. with
> >> the body of the message (first line only): unsubscribe
> >> See http://www.seismicnet.com/maillist.html for more information.
> >>
> >
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
>
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Reinforced concrete base for Lehman instrument
From: beezaur beezaur@..........
Date: Sat, 08 Mar 2003 20:48:40 -0800
>
>
> Carbon could be OK, but how do you plan to make the fittings?
> Metal is easier to fabricate and fit. You can easily get nickel plated
> piano wire down to 8 thou. from a music shop, it does not have any
> 'bending' memory and it works just fine. See http://www.daddario.com/
> Suggest that you forget kevlar or other plastics. A ball bearing in the
> end of the arm gives an excellent bottom suspension up against a
> stainless steel razor blade glued flat onto the crossbar.
>
> Regards,
>
> Chris Chapman
Chris,
You are right that steel is more rigid than concrete, by about 8x, but a
cement/sand base has easily 8x the cross sectional area of steel, so
becomes more rigid because of its greater size.
Arrow shafts can be ordered hollow. You would normally glue in a
threaded insert (female) for the tip and push in a nock. One could
easily glue in two tip inserts. Glue a ball bearing on one end and
thread the other to the mass. You can drill a hole in a lead weight and
glue an arrow tip in that. This way the boom (by this I mean just the
compression member between the mast and weight) has a natural period in
the tens of Hz and has next to no mass, so should not bother the pickup
hardware, even if it does vibrate some. Also, making the boom so much
lighter than the weight at the end should help sensitivity.
As for tension member, My thought is that using bowstring material
(650,000 psi breaking strength vs. maybe 100,000 psi for steel) simply
reduces the mass and therefore increases the natural frequency. I have
all this stuff anyway for my bow.
My working hypothesis is that if I make the structure as stiff as
possible and keep all mass on the boom concentrated, I will get a
cleaner signal.
Scott
--
A day without math is like a day without sunshine.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Fw: Folded Pendulum Seismometer
From: "David H. Youden" dyouden@.........
Date: Sun, 09 Mar 2003 07:34:56 -0500
Chris,
I'll try to answer your questions one at a time.
As for the Australian references, try
http://www.cwr.uwa.edu.au/~woo/intro.htmLai
Mun Woo has done interesting research. She is a student of D.G. Blair.
Her page entitled references lists critical papers, notably
"Performance of an ultra low-frequency folded pendulum" by D. G
Blair. This paper is not available on the web as far as I know, but any
good library (books, remember them?) can get it for you.
For the circuit, If Larry gives his OK I'll send him a document
that details the circuitry that I used. It'll take a couple of days to
prepare it for publication, but I will gladly do it if there is interest.
Basically, it is the same stuff that is used for an S-G instrument,
except for the capacitance gauge stuff.
My information on setup and performance is limited. Basically setup
involves levelling the instrument and then adjusting the counterweight to
achieve the maximum sustainable period of oscillation (With the feedback
turned off). Then you connect the feedback and adjust its level for
critical damping. I have not spent a lot of time characterizing the
performance of the device. It is more sensitive than the big Lehman that
sits next to it, but beyond that, there is little that I can tell
you.
My use of aquarium cement comes from Roger Baker's work on his
Gravimeter/Seismometer. Here's a quote from his web site, which is
currently at
http://www.njsas.org/projects/tidal_forces/magnetic_gravimeter/baker/
.. I built a copy of his rig, but was unhappy with its performance.
"CONSTRUCTION DETAILS
Note: One unusual feature of the construction of practically my entire instrument is the use of silicone rubber as an adhesive, frequently in combination with glass. Many kinds of instrumental prototypes can be constructed with nothing more than glass carefully cut with a carbide wheel cutter, and perhaps ground with a diamond wheel to give a precision fit, and finally bonded with silicone rubber to to give a permanent and slightly flexible bond. Most of the metal parts can be cut with a jeweler's saw and soldered as needed.
Whereas some be tempted to think that prototypes made in this way would be floppy instead of rigid, this is not so. The thing to keep in mind is that glass is cheap, very easy to cut, easy to grind to fit, and very stiff and permanent, and that thixotropic silicone rubber makes setup easy while giving a nearly perfect bond. If there are rules to be kept in mind when doing such work, they are probably the need to use enough pressure always keep the rubber bonds very thin, and to make use of right angle pieces of glass to brace the various components of the instrument. If this is all kept in mind it will be found possible to rapidly build prototypes that are just as rigid and more permanent, in many cases, than similar structures made of metal, and also rapidly and with very few tools being required. It is possible to force a razor blade into the bond and disassemble and then reassemble the various components in a slightly different position if necessary."
I hope this all helps, Stay in touch, and, with Larry's approval, I'll do something about the electronics.
Dave...
Subject: RE: Reinforced concrete base for Lehman instrument
From: "Jan D. Marshall" jandmarshall@............
Date: Sun, 9 Mar 2003 08:12:30 -0700
You might consider a marble slab for the base of the instrument. That is
what I used. You can generally find scrap pieces at a stone dealer. Mine
is 18"x36"x1 1/2" white marble. It was easy to work with. You can grill it
with regular masonry bits and it has good mass. Best of all it was not
expensive -- about $30.
http://24.116.175.108/idahopsn1.htm then click on "My site for pictures"
Jan Marshall
jandmarshall@............
http://myweb.cableone.net/jandmarshall/
Nampa, ID
-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@.................
Behalf Of ChrisAtUpw@.......
Sent: Saturday, March 08, 2003 3:22 PM
To: psn-l@..............
Subject: Re: Reinforced concrete base for Lehman instrument
In a message dated 08/03/03, beezaur@.......... writes:
> temperature changes. I would be most surprised if 1:1 sand and cement
> was not strong enough in practice, . . .
> Have you considered making a T base frame out of say 1.5" black
> steel angle? . . .
> Regards,
> Chris Chapman
Chris,
Thank you.
I think you are right about the grout mix being strong on its own. It
isn't a trick to get regular concrete to 6000 psi compressive strength
(garden variety being 2000-3000 psi), and in fact the stone is what usually
breaks first in the really high strength stuff. I still worry about
brittleness - this device will have to survive a couple of moves in the next
few years. How much water is typically used?
Unless you drop it or hit it with a hammer, I would not expect
brittleness to be a serious problem. I don't know about the water. It needs
to be saturated. I used an eccentric dowel on an electric drill to agitate
the mix and get the air out. It has a surface which is just liquid.
Since rebar is a problem in concrete for the base, I assume I don't have
to ask about pouring the pier over 8 ft R/C pilings to better couple with
more stable ground at depth. It sounds to me like the soil/piling interface
would have the same noise problems as rebar/concrete. But please correct me
if that technique has proven reliable.
I do not know. The moisture variations could be considerable, but
the temperature variations are likely to be small. You also have tilt to
consider. This may be a limiting factor in the period you can use. I would
place a plinth on the earth / subsoil clear of any piles.
Steel or aluminum is "plan B" for the base of the instrument. The
support for the boom will be a metal tripod, bolted to the base. I would
like to keep the natural (resonant) frequency of that structure very high,
kHz if possible. I want to put my pickup and damping hardware on the same
base as the boom, hence the 40 in length. I hadn't expected a "T" to get me
there, but the design you describe may well be stiff enough, especially with
channel or square structural tubing.
I suggest that you stick to steel. It is much more rigid. A
completely rectangular design is the easiest to construct. A simple design
with the least problems is more likely to get built! You can fit 6 to 8"
lengths of flat plate between the horizontal and vertical parallels to
greatly increase the rigidity and provide a pan for mounting sensors or
damping devices. You could use 1" L to brace the top of the U hoop to the
end of the T arm. Could one of the drive on steel ramps sold for car / truck
maintenance be converted - they come ready welded? Just a wild idea!
Another thought: has anyone considered using carbon arrow shafts or
kevlar / spectra bowstring for boom components? They are pretty cheap now,
and their strength-to-weight ratios give them very good vibration
characteristics, and some bowstring absolutely does not creep.
Carbon could be OK, but how do you plan to make the fittings? Metal
is easier to fabricate and fit. You can easily get nickel plated piano wire
down to 8 thou. from a music shop, it does not have any 'bending' memory and
it works just fine. See http://www.daddario.com/ Suggest that you forget
kevlar or other plastics. A ball bearing in the end of the arm gives an
excellent bottom suspension up against a stainless steel razor blade glued
flat onto the crossbar.
Regards,
Chris Chapman
You=20
might consider a marble slab for the base of the instrument. That =
is what=20
I used. You can generally find scrap pieces at a stone =
dealer. Mine=20
is 18"x36"x1 1/2" white marble. It was easy to work with. =
You can=20
grill it with regular masonry bits and it has good mass. Best of =
all it=20
was not expensive -- about $30.
Jan Marshall jandmarshall@............ http://myweb.cableone.net=
/jandmarshall/ Nampa, ID
-----Original Message----- From: =
psn-l-request@.................
[mailto:psn-l-request@...............On Behalf Of=20
ChrisAtUpw@....... Sent: Saturday, March 08, 2003 3:22=20
PM To: psn-l@.............. Subject: Re: =
Reinforced=20
concrete base for Lehman instrument
In a message dated 08/03/03,=20
beezaur@.......... writes:
> temperature changes. I would be most surprised if =
1:1 sand=20
and cement > was not strong enough in practice, . . . =
>=20
Have you considered making a T =
base=20
frame out of say 1.5" black > steel angle? . . . >=20
Regards, >=20
Chris Chapman
Chris,=20
Thank you.
I think you are right about the grout mix =
being=20
strong on its own. It isn't a trick to get regular concrete to 6000 =
psi=20
compressive strength (garden variety being 2000-3000 psi), and in =
fact the=20
stone is what usually breaks first in the really high strength =
stuff.=20
I still worry about brittleness - this device will have to =
survive a=20
couple of moves in the next few years. How much water is typically=20
used?
Unless =
you drop=20
it or hit it with a hammer, I would not expect brittleness to be a =
serious=20
problem. I don't know about the water. It needs to be saturated. I =
used an=20
eccentric dowel on an electric drill to agitate the mix and get the =
air out.=20
It has a surface which is just liquid.
Since rebar is a problem in concrete for the base, I =
assume I=20
don't have to ask about pouring the pier over 8 ft R/C pilings to =
better=20
couple with more stable ground at depth. It sounds to me like =
the=20
soil/piling interface would have the same noise problems as =
rebar/concrete.=20
But please correct me if that technique has proven=20
reliable.
I do =
not=20
know. The moisture variations could be considerable, but the =
temperature=20
variations are likely to be small. You also have tilt to consider. =
This may be=20
a limiting factor in the period you can use. I would place a plinth on =
the=20
earth / subsoil clear of any piles.
Steel or aluminum is "plan B" for the base of the =
instrument.=20
The support for the boom will be a metal tripod, bolted to the base. =
I would=20
like to keep the natural (resonant) frequency of that structure very =
high,=20
kHz if possible. I want to put my pickup and damping hardware on the =
same=20
base as the boom, hence the 40 in length. I hadn't expected a "T" to =
get me=20
there, but the design you describe may well be stiff enough, =
especially with=20
channel or square structural=20
tubing.
I =
suggest that=20
you stick to steel. It is much more rigid. A completely rectangular=20
design is the easiest to construct. A simple design with the =
least=20
problems is more likely to get built! You can fit 6 to 8" lengths of =
flat=20
plate between the horizontal and vertical parallels to greatly =
increase the=20
rigidity and provide a pan for mounting sensors or damping devices. =
You could=20
use 1" L to brace the top of the U hoop to the end of the T arm. Could =
one of=20
the drive on steel ramps sold for car / truck maintenance be converted =
- they=20
come ready welded? Just a wild idea!
Another thought: has anyone considered using carbon =
arrow shafts=20
or kevlar / spectra bowstring for boom components? They are pretty =
cheap=20
now, and their strength-to-weight ratios give them very good =
vibration=20
characteristics, and some bowstring absolutely does not =
creep.
Carbon =
could be OK,=20
but how do you plan to make the fittings? Metal is easier to fabricate =
and=20
fit. You can easily get nickel plated piano wire down to 8 thou. from =
a music=20
shop, it does not have any 'bending' memory and it works just fine. =
See=20
http://www.daddario.com/ Suggest that you forget kevlar or other =
plastics. A=20
ball bearing in the end of the arm gives an excellent bottom =
suspension up=20
against a stainless steel razor blade glued flat onto the crossbar.=20
Regards,=20
Chris Chapman=20
Subject: Volcan Baru Array Update
From: "a.rodriguez" stuff@.................
Date: Sun, 9 Mar 2003 10:44:52 -0500
Hello Everyone,
I have made added to the Volcan Baru array page.
Most of the last month and a half have been spent on digging the
ditches and laying the cables, along with making the central station
box. I also have the computer system which will run the array. It is totally
motorless. No fans or hard drives to fail.
The electronics for the stations are done and the next step will be to
assemble the whole system here and test it. Check the polarities and
phase relation of the system and then install it in the field. I suspect that
it will be another month or two before the array is functional. Carla
is remodeling the kitchen and lots of my time and attention is going
to that.
The link to the array page is www.volcanbaru.com/array/array.html you
can go right to the updated part by clicking on the link right at the
top of the opening page.
As always all comments and
suggestions welcome.
Best regards,
Angel
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Reinforced concrete base for Lehman instrument
From: "kpayea" kpayea@...........
Date: Sun, 9 Mar 2003 10:36:01 -0800
I built the base of my STM-8 style vertical Seismometer out of concrete
also, and I have had very good results from it. However, instead of casting
a solid piece, I used a combination of 8" x 8" and 8" x 16" concrete
stepping stones and a few concrete bricks. The base is made of two layers
of stepping stones - one of the 8x8 and one 8x16 in each layer - arranged so
the joints don't overlap. The finished base is 8x24 by about 3" thick.
The tower at one end to support the boom hinge is a stack of concrete
bricks. The parts are not mortared together, but are held with "liquid
nails" style adhesive. There is a special formula made for masonry. I let
all of the joins cure for about a week.
The advantage of this style is that there is no mortar to mix and no forms
to create.
I used steel "T" nuts for attachment points, epoxied into holes drilled in
the concrete parts.
I know this probably breaks several "rules" about seismometer construction,
but it works very well. I think the concrete acts as a thermal mass,
evening out small temperature variations and reducing the temperature
sensitivity. It has been running for a couple of years with no adjustments
to the sensor itself. I do adjust the offset in SDR seasonally as the
ambient temperature changes.
It sure is heavy!
Good luck,
Keith
----- Original Message -----
From: "beezaur"
To:
Sent: Saturday, March 08, 2003 8:48 PM
Subject: Re: Reinforced concrete base for Lehman instrument
>
> >
> >
> > Carbon could be OK, but how do you plan to make the fittings?
> > Metal is easier to fabricate and fit. You can easily get nickel plated
> > piano wire down to 8 thou. from a music shop, it does not have any
> > 'bending' memory and it works just fine. See http://www.daddario.com/
> > Suggest that you forget kevlar or other plastics. A ball bearing in the
> > end of the arm gives an excellent bottom suspension up against a
> > stainless steel razor blade glued flat onto the crossbar.
> >
> > Regards,
> >
> > Chris Chapman
>
> Chris,
>
> You are right that steel is more rigid than concrete, by about 8x, but a
> cement/sand base has easily 8x the cross sectional area of steel, so
> becomes more rigid because of its greater size.
>
> Arrow shafts can be ordered hollow. You would normally glue in a
> threaded insert (female) for the tip and push in a nock. One could
> easily glue in two tip inserts. Glue a ball bearing on one end and
> thread the other to the mass. You can drill a hole in a lead weight and
> glue an arrow tip in that. This way the boom (by this I mean just the
> compression member between the mast and weight) has a natural period in
> the tens of Hz and has next to no mass, so should not bother the pickup
> hardware, even if it does vibrate some. Also, making the boom so much
> lighter than the weight at the end should help sensitivity.
>
> As for tension member, My thought is that using bowstring material
> (650,000 psi breaking strength vs. maybe 100,000 psi for steel) simply
> reduces the mass and therefore increases the natural frequency. I have
> all this stuff anyway for my bow.
>
> My working hypothesis is that if I make the structure as stiff as
> possible and keep all mass on the boom concentrated, I will get a
> cleaner signal.
>
> Scott
>
> --
> A day without math is like a day without sunshine.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: Reinforced concrete base for Lehman instrument
From: steve hammond shammon1@.............
Date: Sun, 9 Mar 2003 11:07:20 -0800
When we had a PSN meeting at Berkeley University, the folks in the lab told
us that the broadband seismographs were placed on a 50/50 sand/cement mix.
Regards, Steve Hammond PSN San Jose, Aptos California
-----Original Message-----
From: kpayea [SMTP:kpayea@............
Sent: Sunday, March 09, 2003 10:36 AM
To: psn-l@..............
Subject: Re: Reinforced concrete base for Lehman instrument
I built the base of my STM-8 style vertical Seismometer out of concrete
also, and I have had very good results from it. However, instead of
casting
a solid piece, I used a combination of 8" x 8" and 8" x 16" concrete
stepping stones and a few concrete bricks. The base is made of two layers
of stepping stones - one of the 8x8 and one 8x16 in each layer - arranged
so
the joints don't overlap. The finished base is 8x24 by about 3" thick.
The tower at one end to support the boom hinge is a stack of concrete
bricks. The parts are not mortared together, but are held with "liquid
nails" style adhesive. There is a special formula made for masonry. I let
all of the joins cure for about a week.
The advantage of this style is that there is no mortar to mix and no forms
to create.
I used steel "T" nuts for attachment points, epoxied into holes drilled in
the concrete parts.
I know this probably breaks several "rules" about seismometer
construction,
but it works very well. I think the concrete acts as a thermal mass,
evening out small temperature variations and reducing the temperature
sensitivity. It has been running for a couple of years with no adjustments
to the sensor itself. I do adjust the offset in SDR seasonally as the
ambient temperature changes.
It sure is heavy!
Good luck,
Keith
----- Original Message -----
From: "beezaur"
To:
Sent: Saturday, March 08, 2003 8:48 PM
Subject: Re: Reinforced concrete base for Lehman instrument
>
> >
> >
> > Carbon could be OK, but how do you plan to make the fittings?
> > Metal is easier to fabricate and fit. You can easily get nickel plated
> > piano wire down to 8 thou. from a music shop, it does not have any
> > 'bending' memory and it works just fine. See http://www.daddario.com/
> > Suggest that you forget kevlar or other plastics. A ball bearing in the
> > end of the arm gives an excellent bottom suspension up against a
> > stainless steel razor blade glued flat onto the crossbar.
> >
> > Regards,
> >
> > Chris Chapman
>
> Chris,
>
> You are right that steel is more rigid than concrete, by about 8x, but a
> cement/sand base has easily 8x the cross sectional area of steel, so
> becomes more rigid because of its greater size.
>
> Arrow shafts can be ordered hollow. You would normally glue in a
> threaded insert (female) for the tip and push in a nock. One could
> easily glue in two tip inserts. Glue a ball bearing on one end and
> thread the other to the mass. You can drill a hole in a lead weight and
> glue an arrow tip in that. This way the boom (by this I mean just the
> compression member between the mast and weight) has a natural period in
> the tens of Hz and has next to no mass, so should not bother the pickup
> hardware, even if it does vibrate some. Also, making the boom so much
> lighter than the weight at the end should help sensitivity.
>
> As for tension member, My thought is that using bowstring material
> (650,000 psi breaking strength vs. maybe 100,000 psi for steel) simply
> reduces the mass and therefore increases the natural frequency. I have
> all this stuff anyway for my bow.
>
> My working hypothesis is that if I make the structure as stiff as
> possible and keep all mass on the boom concentrated, I will get a
> cleaner signal.
>
> Scott
>
> --
> A day without math is like a day without sunshine.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Folded pendulum
From: "Ted Rogers" TedR@..................
Date: Mon, 10 Mar 2003 11:44:38 +1000
All
Check 'The Amateur Scientist' in the April 1967 issue of 'Scientific
American'. It would appear the author - Nils E. Lindenblad should may be
credited with the invention of this type of pendulum. The article also shows
another type of long period pendulum, one free to swing in any direction .
Hope you find the article as interesting as I did, in fact my first attempt
at building a seismograph was based on his design - it failed miserably as
I thought the suspension illustrated would have to much friction I tried
other types - each one being worse than the other, so in the end I gave it
away.
I shall have another try but this time I'll try foil type suspensions.
.
------------
Regards
Ted Rogers.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Archery Components
From: "Randall Pratt" rpratt@.............
Date: Sun, 9 Mar 2003 19:49:18 -0600
Scott,
I have tried both aluminum and carbon arrow shafts. It's easy to make =
fittings from aluminum sheet by wrapping it around a proper sized bolt =
or by using glass cloth and resin but you will have to use care in the =
design. I have about 2 kg mass and the forces in the boom are to great =
for an arrow shaft (2215 xx75 about 28" long for example) with my =
support configuration. If you do try the arrow, use a bit taller mast =
and fasten the support wire to the mass with the force line through the =
CG. Hanging the mass outside the wire will induce a bending moment =
which combined with the compression is more than the shaft will handle. =
I went to 1/2" x .035" wall aluminum tube simply because the arrow with =
2 kg on the end is very delicate. I did continue to use an arrow insert =
epoxied into the partially compressed tube end and a field point as the =
pivot riding on an aircraft bolt head. The point on the field tip is =
not satisfactory as machined and also tends to damage easily during =
setup due to softness. I have reground and hardened the temper and =
intend to add a tool steel point. With the insert it is only seconds to =
change the pivot. =20
I've considered the string material also but for me the cost is still =
out of line with any potential improvement. If you have string material =
on hand, the strength and stretch properties certainly would make it =
worth a try. It has totally replaced steel cables in archery for the =
same qualities of light weight, strength, and low stretch.
Welding up a base from steel angle is easy and practical. I made a =
horizontal T and added an upright. It doesn't take 30 minutes. My =
leveling screws are threaded into the T but you could also epoxy or tack =
weld nuts to the angle.
Randy
Scott,
I have tried both aluminum and carbon =
arrow=20
shafts. It's easy to make fittings from aluminum sheet by wrapping =
it=20
around a proper sized bolt or by using glass cloth and resin but =
you will=20
have to use care in the design. I have about 2 kg mass and the =
forces in=20
the boom are to great for an arrow shaft (2215 xx75 about 28" long =
for=20
example) with my support configuration. If you do try the arrow, =
use a bit=20
taller mast and fasten the support wire to the mass with the force line =
through=20
the CG. Hanging the mass outside the wire will induce a bending =
moment=20
which combined with the compression is more than the shaft will =
handle. =20
I went to 1/2" x .035" wall aluminum tube simply because the =
arrow=20
with 2 kg on the end is very delicate. I did continue to use an =
arrow=20
insert epoxied into the partially compressed tube end and a field point =
as the=20
pivot riding on an aircraft bolt head. The point on the field tip =
is not=20
satisfactory as machined and also tends to damage easily during setup =
due to=20
softness. I have reground and hardened the temper and intend to add =
a tool=20
steel point. With the insert it is only seconds to change the =
pivot. =20
I've considered the string material =
also but for me=20
the cost is still out of line with any potential improvement. If =
you have=20
string material on hand, the strength and stretch properties =
certainly=20
would make it worth a try. It has totally replaced =
steel=20
cables in archery for the same qualities of light weight, strength, =
and low=20
stretch.
Welding up a base from steel angle is =
easy and=20
practical. I made a horizontal T and added an upright. =
It=20
doesn't take 30 minutes. My leveling screws are threaded into the =
T but=20
you could also epoxy or tack weld nuts to the angle.
Randy
Subject: Re: Folded pendulum
From: "David H. Youden" dyouden@.........
Date: Mon, 10 Mar 2003 17:21:05 -0500
Ted,
I appreciate the tip. I have a copy of the article and will try to
investigate further to see if Nils really did invent this device.
Dave...
At 11:44 AM 3/10/03 +1000, you wrote:
>All
>
>Check 'The Amateur Scientist' in the April 1967 issue of 'Scientific
>American'. It would appear the author - Nils E. Lindenblad should may be
>credited with the invention of this type of pendulum. The article also shows
>another type of long period pendulum, one free to swing in any direction .
>Hope you find the article as interesting as I did, in fact my first attempt
>at building a seismograph was based on his design - it failed miserably as
>I thought the suspension illustrated would have to much friction I tried
>other types - each one being worse than the other, so in the end I gave it
>away.
>I shall have another try but this time I'll try foil type suspensions.
>.
>------------
>
>Regards
>
>Ted Rogers.
>
>
>
>
>
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Fw: Folded Pendulum Seismometer
From: "David H. Youden" dyouden@.........
Date: Tue, 11 Mar 2003 06:08:30 -0500
At 02:05 AM 3/10/03 -0500, you wrote:
In
a message dated 09/03/03, dyouden@......... writes:
As for the Australian references,
try
http://www.cwr.uwa.edu.au/~woo/intro.htm
Lai Mun Woo has done interesting research. She is a student of D.G.
Blair. Her page entitled references lists critical papers, notably
"Performance of an ultra low-frequency folded pendulum" by D. G
Blair. This paper is not available on the web as far as I know, but any
good library (books, remember them?) can get it for
you.
Hi Dave,
Thanks very much for the
references. When I call up the Woo reference and go to 'Seismographic
Instrumentation', I just get empty squares instead of diagrams or photos.
Do you get the same problems? Also, I can't print the text directly. I
have to copy it and then print it. There must be something odd about the
text, since I have not had this problem before.
Chris, I have
experienced the same problem. I think that the server is just very slow
at downloading the diagrams. As for the text, I had to do just what you
did - cut and paste the paper together. A pain, but worth the effort, I
thought.
For
the circuit, If Larry gives his OK I'll send him a document that details
the circuitry that I used. It'll take a couple of days to prepare it for
publication, but I will gladly do it if there is interest. Basically, it
is the same stuff that is used for an S-G instrument, except for the
capacitance gauge stuff.
I would certainly be
interested, please. There are few modern circuits about and an up to date
capacitative transducer would be a valuable addition. John Lahr has a
very useful website and is most helpful.
Both Larry, and John Lahr have agreed to post the electronics, so as soon
as I get them in shape you'll have the documentation.
What is the operating frequency of the transducer? Is it a phase
sensitive detector?
The operating frequency is 50 Khz, and yes, it is a phase sensitive
detector.
My
information on setup and performance is limited. Basically setup involves
levelling the instrument and then adjusting the counterweight to achieve
the maximum sustainable period of oscillation (With the feedback turned
off). Then you connect the feedback and adjust its level for critical
damping. I have not spent a lot of time characterising the performance of
the device. It is more sensitive than the big Lehman that sits next to
it, but beyond that, there is little that I can tell
you.
You do not use a triple
feedback loop then? What seismic mass do you use?
I am not familiar with the
term 'centre of percussion'?
By triple feedback I presume you mean PID. I messed with a PID loop, but
could see no real advantage, so I have used a proportional-differential
system.
The total mass of the carriage and the adjustable weight is about 550
grams, not much but enough for the purpose.
My
use of aquarium cement comes from Roger Baker's work on his
Gravimeter/Seismometer. Here's a quote from his web site, which is
currently at
http://www.njsas.org/projects/tidal_forces/magnetic_gravimeter/baker/
.. I built a copy of his rig, but was unhappy with its performance.
Roger had plenty of enthusiasm, but his work seemed to be over hyped by Carlson at Scientific American. He was right about a lot of things, but also wrong about several.
You can get a polyurethane mastic called Sikaflex, used on yachts, which sets by moisture, is extremely strong and sticks most things. You can also stick glass with epoxy and get extremely strong joints. Epoxy does not stick to water at all well and cold glass has several layers of the stuff. The trick is to bake the glass to 150 C in an electric oven, take it out with cotton gloves and immediately stick it with a slow setting epoxy. Al also benefits from this treatment.
Thanks for this tip. I'll try it. I'm sure that it will work.
I hope this all helps, Stay in touch, and, with Larry's approval, I'll do something about the electronics.
It helps considerably, thank you. That would be great.
Regards,
Chris Chapman
Have a good one,
Dave...
Subject: QUAKE
From: David A Nelson davenn@...............
Date: Tue, 11 Mar 2003 23:49:25 +1100
Large event New Ireland area ~ M6.7-6.9 SW Pacific
~ 07:27 UT
Dave
In God I trust; All others pay cash :)
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Winquake 2.9.4
From: RLLaney@.......
Date: Wed, 12 Mar 2003 18:31:18 EST
Hi Larry:
I am having trouble emailing event files. In the Open File window, the Send
Email button is not on. Anyone else having this problem? Am I overlooking
something?
Thanks.
Bob Laney
Salem, Oregon
Hi Larry:
I am having trouble emailing event files. In the Open File window, the=
Send Email button is not on. Anyone else having this problem? A=
m I overlooking something?
Thanks.
Bob Laney
Salem, Oregon
Subject: Large Quake Rolling In
From: Jeff Batten jeff.batten@........
Date: Wed, 12 Mar 2003 16:06:03 -0800
Hello
Have a large quake rolling in, looks big.
Jeff
Jeff Batten
Senior Electronics Technician
CSUN Physics and Astronomy
San Fernando Observatory
818-677-2768
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Redwood trace
From: Stephen & Kathy skmort@..........
Date: Wed, 12 Mar 2003 16:07:23 -0800
Larry,, I'm receiving a good sized event from somewhere,, (can't hook up to
the world webecorders??), thought I would check your online traces,,, noticed
that your trace wasn't showing anything of this event, which should have started
at approx. 15:44 PST in your area?????? What is the story???
Stephen
PSN Station #55
near Pilot Hill Ca
38.828N 120.979W
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: concrete tests
From: beezaur beezaur@..........
Date: Wed, 12 Mar 2003 16:50:54 -0800
Hi all,
Just an FYI in case you are interested. I will be testing the material
properties of the 1:1 sand:cement mix used for seismometer peirs and
sometimes as a structural member of the device itself.
I will be testing cylinders in a compression test which gives elastic
modulus and compressive strength directly. It also gives a good
estimate of tensile strength and toughness. The plan is to test one
batch moist cured for 28 days and one batch air cured for after 7 days
of moist cure. Thermal properties will have to wait, as there is still
a lot of gel in the mix at 28 days.
If anyone would like to see any variations on the above, please let me
know. I will be filling molds by 20-Mar.
Scott
--
A day without math is like a day without sunshine.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: concrete tests
From: "Gary Lindgren" gel@.................
Date: Wed, 12 Mar 2003 17:01:39 -0800
Scott,
What strength are you looking for the mix you used. Was there any rock in
the mix.
Gary
-----Original Message-----
From: psn-l-request@..............
[mailto:psn-l-request@................. Behalf Of beezaur
Sent: Wednesday, March 12, 2003 4:51 PM
To: PSN-L@..............
Subject: concrete tests
Hi all,
Just an FYI in case you are interested. I will be testing the material
properties of the 1:1 sand:cement mix used for seismometer peirs and
sometimes as a structural member of the device itself.
I will be testing cylinders in a compression test which gives elastic
modulus and compressive strength directly. It also gives a good
estimate of tensile strength and toughness. The plan is to test one
batch moist cured for 28 days and one batch air cured for after 7 days
of moist cure. Thermal properties will have to wait, as there is still
a lot of gel in the mix at 28 days.
If anyone would like to see any variations on the above, please let me
know. I will be filling molds by 20-Mar.
Scott
--
A day without math is like a day without sunshine.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: concrete tests
From: beezaur beezaur@..........
Date: Wed, 12 Mar 2003 17:34:57 -0800
Gary Lindgren wrote:
> Scott,
> What strength are you looking for the mix you used. Was there any rock in
> the mix.
> Gary
>
Gary,
No rock at all - I'm aiming for a matrix supported composite of (mostly)
quartz sand and portland cement. I'm hoping for over 6000 psi
compressive strength at 28 days. Ready-mix from a truck is usually 3000
to 4000 psi. If the difference in moist cured and air cured is
substantial (should be), then further moist curing might produce
significantly more strength. Some mixes will gain another 60% in
compressive strength if moist cured for a full year.
The compressive strength is not as much the goal as tensile strength and
toughness, which both go up with compressive strength. Unreinforced
concrete beams like this usually fail in tension at the bottom, often
from repeated light loads which cause hairline cracks to form and
propagate. Basically, I want to know how light I can make the base for
my Lehman type device and still be confident it won't break with normal
handling and thermal changes.
My wife makes root beer, I make fake rock.
Scott
--
A day without math is like a day without sunshine.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: concrete tests
From: ChrisAtUpw@.......
Date: Wed, 12 Mar 2003 21:00:11 EST
In a message dated 13/03/03, beezaur@.......... writes:
> I'm aiming for a matrix supported composite of (mostly) quartz sand and
> portland cement.
Hi Scott,
Is the curing rate and the final properties significantly temperature
dependant?
Are the properties of the top surface any different from the moulded
surfaces?
Can you inhibit surface micro cracking by coating the inside of the
mould with carbon or other fibres? Alternatively, can you post coat with
carbon or glass to any advantage?
Regards,
Chris Chapman
In a message dated 13/03/=
03, beezaur@.......... writes:
I'm aiming for a matrix sup=
ported composite of (mostly) quartz sand and portland cement.
<=
FONT COLOR=3D"#000000" SIZE=3D3 FAMILY=3D"SANSSERIF" FACE=3D"Arial" LANG=
=3D"0">
Hi Scott,
Is the curing rate and the final pr=
operties significantly temperature dependant?=20
Are the properties of the top surfa=
ce any different from the moulded surfaces?
Can you inhibit surface micro crack=
ing by coating the inside of the mould with carbon or other fibres? Alternat=
ively, can you post coat with carbon or glass to any advantage?=20
Regards,
Chris Chapman &nb=
sp;
Subject: breaking news
From: allan egleston allane@.........
Date: Wed, 12 Mar 2003 17:59:45 -0800
6.1 in the gulf of california
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Redwood trace
From: "Larry Cochrane" cochrane@..............
Date: Wed, 12 Mar 2003 18:01:06 -0800
Stephen,
The event is on my current seismicity page. My sensors as well as other PSN
stations recorded the event just fine. You should be able to see it on this
page http://www.seismicnet.com/currentseismicity.html.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Stephen & Kathy"
To: "PSN-list"
Sent: Wednesday, March 12, 2003 4:07 PM
Subject: Redwood trace
> Larry,, I'm receiving a good sized event from somewhere,, (can't hook up
to
> the world webecorders??), thought I would check your online traces,,,
noticed
> that your trace wasn't showing anything of this event, which should have
started
> at approx. 15:44 PST in your area?????? What is the story???
> Stephen
> PSN Station #55
> near Pilot Hill Ca
> 38.828N 120.979W
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Redwood trace
From: Stephen & Kathy skmort@..........
Date: Wed, 12 Mar 2003 18:24:28 -0800
Those traces look great,,, so what is the trace at:
http://www.seismicnet.com/
It looks like it is updating correctly, but there is no hint of the 15:44 PST
event??????
Stephen
Larry Cochrane wrote:
>
> Stephen,
>
> The event is on my current seismicity page. My sensors as well as other PSN
> stations recorded the event just fine. You should be able to see it on this
> page http://www.seismicnet.com/currentseismicity.html.
>
> -Larry Cochrane
> Redwood City, PSN
>
> ----- Original Message -----
> From: "Stephen & Kathy"
> To: "PSN-list"
> Sent: Wednesday, March 12, 2003 4:07 PM
> Subject: Redwood trace
>
> > Larry,, I'm receiving a good sized event from somewhere,, (can't hook up
> to
> > the world webecorders??), thought I would check your online traces,,,
> noticed
> > that your trace wasn't showing anything of this event, which should have
> started
> > at approx. 15:44 PST in your area?????? What is the story???
> > Stephen
> > PSN Station #55
> > near Pilot Hill Ca
> > 38.828N 120.979W
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Redwood trace
From: J D Cooley cooleyj@....................
Date: Wed, 12 Mar 2003 18:51:55 -0800
At 06:24 PM 3/12/03, you wrote:
>Those traces look great,,, so what is the trace at:
>
>http://www.seismicnet.com/
>
>It looks like it is updating correctly, but there is no hint of the 15:44 PST
>event??????
> Stephen
2003/03/12 23:41 M 6.1 GULF OF CALIFORNIA Z= 10km 26.34N 110.64W
This information is provided by the USGS
National Earthquake Information Center.
(Address problems to: sedas@....................
These parameters are preliminary and subject to revision.
A magnitude 6.1 earthquake IN GULF OF CALIFORNIA has occurred at:
26.34N 110.64W Depth 10km Wed Mar 12 23:41:30 2003 UTC
Time: Universal Time (UTC) Wed Mar 12 23:41:30 2003
Time Near Epicenter Wed Mar 12 16:41:30 2003
Eastern Standard Time (EST) Wed Mar 12 18:41:30 2003
Central Standard Time (CST) Wed Mar 12 17:41:30 2003
Mountain Standard Time (MST) Wed Mar 12 16:41:30 2003
Pacific Standard Time (PST) Wed Mar 12 15:41:30 2003
Alaska Standard Time (AST) Wed Mar 12 14:41:30 2003
Hawaii Standard Time (HST) Wed Mar 12 13:41:30 2003
Location with respect to nearby cities:
80 km (50 miles) ENE of Loreto, Baja Calif. Sur, Mexico (pop 10,000)
140 km (90 miles) SSW of Ciudad Obregon, Sonora, Mexico (pop 250,000)
140 km (90 miles) SW of Navojoa, Sonora, Mexico (pop 98,000)
1410 km (870 miles) NW of MEXICO CITY, D.F., Mexico
"JD" Cooley
__________________________________________________________
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Subject: Re: Winquake 2.9.4
From: "Larry Cochrane" cochrane@..............
Date: Wed, 12 Mar 2003 19:00:28 -0800
Hi Bob,
This is a problem with WinQuake. I never use this feature so I didn't =
notice that the button is always grayed out. I'll have a new version out =
in a few days.=20
-Larry Cochrane
Redwood City, PSN
----- Original Message -----=20
From: RLLaney@..........
To: psn-l@.................
Sent: Wednesday, March 12, 2003 3:31 PM
Subject: Winquake 2.9.4
Hi Larry:
I am having trouble emailing event files. In the Open File window, =
the Send Email button is not on. Anyone else having this problem? Am I =
overlooking something?
Thanks.
Bob Laney
Salem, Oregon
Hi Bob,
This is a problem with WinQuake. I =
never use this=20
feature so I didn't notice that the button is always grayed out. I'll =
have a new=20
version out in a few days.
I am having trouble emailing =
event=20
files. In the Open File window, the Send Email button is not =
on. =20
Anyone else having this problem? Am I overlooking=20
something?
Thanks.
Bob Laney Salem, Oregon=20
Subject: Re: Redwood trace
From: "Larry Cochrane" cochrane@..............
Date: Wed, 12 Mar 2003 19:17:25 -0800
The image on my main page is from a strong motion accelerometer, so it does
not record teleseismic event very will.
-Larry
----- Original Message -----
From: "Stephen & Kathy"
To:
Sent: Wednesday, March 12, 2003 6:24 PM
Subject: Re: Redwood trace
> Those traces look great,,, so what is the trace at:
>
> http://www.seismicnet.com/
>
> It looks like it is updating correctly, but there is no hint of the 15:44
PST
> event??????
> Stephen
>
> Larry Cochrane wrote:
> >
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Would some one like to guess what this might be
From: "Jan D. Marshall" jandmarshall@............
Date: Wed, 12 Mar 2003 21:07:27 -0700
I have an interesting recording from last Thursday.
I dont know how to post the .psn so a few people to look at but I will email
it to those that would lit to see it and give me a guess -- my guess local
blasting but I have never seen anything like this before. (1K file)
Jan Marshall
jandmarshall@............
http://myweb.cableone.net/jandmarshall/
Nampa, ID
I have =
an=20
interesting recording from last Thursday.
I dont =
know how to=20
post the .psn so a few people to look at but I will email it to those =
that would=20
lit to see it and give me a guess -- my guess local blasting but I have =
never=20
seen anything like this before. (1K file)
Jan Marshall jandmarshall@............ http://myweb.cableone.net=
/jandmarshall/ Nampa, ID
Subject: Re: Would some one like to guess what this might be
From: "Larry Cochrane" cochrane@..............
Date: Wed, 12 Mar 2003 20:13:50 -0800
Jan,
PSN formatted event files can be sent to event@.............. for =
archiving on my system. Up to four event files can be sent in at one =
time.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----=20
From: Jan D. Marshall=20
To: Sesmic List Server=20
Sent: Wednesday, March 12, 2003 8:07 PM
Subject: Would some one like to guess what this might be
I have an interesting recording from last Thursday. =20
I dont know how to post the .psn so a few people to look at but I will =
email it to those that would lit to see it and give me a guess -- my =
guess local blasting but I have never seen anything like this before. =
(1K file)
Jan Marshall
jandmarshall@............
http://myweb.cableone.net/jandmarshall/
Nampa, ID=20
Jan,
PSN formatted event files can be sent =
to event@.............. for =
archiving=20
on my system. Up to four event files can be sent in at one =
time.
Subject: Would some one like to =
guess=20
what this might be
I =
have an=20
interesting recording from last Thursday.
I =
dont know how to=20
post the .psn so a few people to look at but I will email it to those =
that=20
would lit to see it and give me a guess -- my guess local blasting but =
I have=20
never seen anything like this before. (1K file)
Jan Marshall jandmarshall@............http://myweb.cableone.net=
/jandmarshall/ Nampa, ID
Subject: RE: Would some one like to guess what this might be
From: "Jan D. Marshall" jandmarshall@............
Date: Wed, 12 Mar 2003 21:21:59 -0700
Thanks -- I sent that one (what.psn) and my capture of the Gulf of Calif
quake today
Jan Marshall
jandmarshall@............
http://myweb.cableone.net/jandmarshall/
Nampa, ID
-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@.................
Behalf Of Larry Cochrane
Sent: Wednesday, March 12, 2003 9:14 PM
To: psn-l@..............
Subject: Re: Would some one like to guess what this might be
Jan,
PSN formatted event files can be sent to event@.............. for
archiving on my system. Up to four event files can be sent in at one time.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: Jan D. Marshall
To: Sesmic List Server
Sent: Wednesday, March 12, 2003 8:07 PM
Subject: Would some one like to guess what this might be
I have an interesting recording from last Thursday.
I dont know how to post the .psn so a few people to look at but I will
email it to those that would lit to see it and give me a guess -- my guess
local blasting but I have never seen anything like this before. (1K file)
Jan Marshall
jandmarshall@............
http://myweb.cableone.net/jandmarshall/
Nampa, ID
Thanks=20
-- I sent that one (what.psn) and my capture of the Gulf of Calif quake=20
today
Jan Marshall jandmarshall@............ http://myweb.cableone.net=
/jandmarshall/ Nampa, ID
-----Original Message----- From: =
psn-l-request@.................
[mailto:psn-l-request@...............On Behalf Of Larry=20
Cochrane Sent: Wednesday, March 12, 2003 9:14 =
PM To:=20
psn-l@.............. Subject: Re: Would some one like to =
guess what=20
this might be
Jan,
PSN formatted event files can be sent =
to event@.............. for =
archiving=20
on my system. Up to four event files can be sent in at one =
time.
Subject: Would some one like =
to guess=20
what this might be
I =
have an=20
interesting recording from last Thursday.
I =
dont know how=20
to post the .psn so a few people to look at but I will email it to =
those=20
that would lit to see it and give me a guess -- my guess local =
blasting but=20
I have never seen anything like this before. (1K =
file)
Jan Marshall jandmarshall@............http://myweb.cableone.net=
/jandmarshall/ Nampa, ID
Subject: Re: Could you give me your opinion of this file
From: "Larry Cochrane" cochrane@..............
Date: Wed, 12 Mar 2003 21:02:01 -0800
Jan,
The strange file looks like a spider quake. I see something like this when a
spider builds a web and uses the Lehman boom as one of the anchor points.
I renamed your Lehman file to 030312.234140.jm1.psn. The station ID and file
extension of Lehman is not a valid station ID code.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "Jan D. Marshall"
To: "Larry Cochrane"
Sent: Wednesday, March 12, 2003 8:39 PM
Subject: Could you give me your opinion of this file
> I think I am learning how to post -- this is my strange file
>
> Jan Marshall
> Nampa, ID
>
> -
> 030306.232958.jm1 \quakes\0303\030306.232959.jm1.psn Upload OK
>
> Thanks for the upload!
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: concrete tests
From: beezaur beezaur@..........
Date: Wed, 12 Mar 2003 21:45:50 -0800
>
> Is the curing rate and the final properties significantly
> temperature dependant?
>
> Are the properties of the top surface any different from the
> moulded surfaces?
>
> Can you inhibit surface micro cracking by coating the inside of
> the mould with carbon or other fibres? Alternatively, can you post coat
> with carbon or glass to any advantage?
>
> Regards,
>
> Chris Chapman
Chris,
Yes, curing is very sensitive to temperature. Type 1 portland cement is
the kind you usually find at the hardware store. It likes to cure in
~40 deg F. Projects cast in hot or cold temperatures require different
types of portland cement aor strength suffers considerably. The final
crystalline structure of the hardened cement is much stronger if it
cures at its design temperature.
The most important factor is the ratio of water to cement by mass in the
mix. A water/cement ratio of 0.7 only gives half the strength of a mix
with a 0.4 ratio. This is more or less independent of proportions of
sand and gravel, which are essentially fillers.
If the concrete is kept moist during cure, the hydration process
proceeds at an exponentially decaying rate. Removal of the moisture
stops the process, but some further curing can take place if moisture is
replaced.
Smoother surfaces contribute to higher strength, but this is usually
most true where the material is under tension. A very rough surface can
locally magnify the stress by a factor of 2 to 3 or more.
As an example, a 12x12 in concrete beam 3 ft long, supported at its
ends, will be under 7 psi tension at the middle of the bottom face from
its own weight. A very rough surface might make this 21 psi locally.
Double this stress (at least) to account for decelleration during
placement. Tensile strength is conservatively 5% of compressive
strength, so a garden-variety, overly watered mix will have a tensile
strength of 0.05 * 1000 psi = 50 psi. Things now look pretty bad for
the garden concrete. Roughness is a factor, but not a large one. The
stuff I hope to make may have a tensile strength of 300 psi. There are
also much more efficient sections - this example weighs 450 lbs.
Explosion and shock resistant structures often have metal "whiskers"
mixed in, and even nylon fibers in the mix will greatly reduce cracking.
External application to the bottom, either before or after casting,
would help by taking the tension load. Bridges work exactly this way,
except that the reinforcement is embedded in the bottom of the beam. A
coat of penetrating, flexible epoxy may be enough.
I worry about noise with reinforcement. Apparently gravel and air
pockets cause noise. There is a possibility that a surface coating
could generate a "surface tension" like that in water. I would expect
fructuations in such tension to cause noise by whatever mechanism rock
and air inclusions produce noise. Or maybe not. It would be an
interesting experiment.
One could mechanically separate the reinforcement from the concrete and
apply the force evenly at the ends of the beam. Prestressed concrete
beams have cables (tendons) which are often run through greased conduit
and fixed to thick end plates under high tension. Tension rods could
easily be centered in longitudinal holes or run outside the beam.
Scott
--
A day without math is like a day without sunshine.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: RE: Winquake 2.9.4
From: steve hammond shammon1@.............
Date: Thu, 13 Mar 2003 00:33:33 -0800
Larry, I ran into two thongs tonight with the beta release. (1) I clicked
on help and the program quit responding and I had to cancel it via the
close program menu. This could be MS ME. Question, help working in the beta
version? (2) Most important, I use this feature all the time. When saving a
file the save menu does not popup as it did in past releases. What happened
to the save only current view option?
Thanks-- Steve Hammond
-----Original Message-----
From: Larry Cochrane [SMTP:cochrane@...............
Sent: Wednesday, March 12, 2003 7:00 PM
To: psn-l@..............
Subject: Re: Winquake 2.9.4
Hi Bob,
This is a problem with WinQuake. I never use this feature so I didn't
notice that the button is always grayed out. I'll have a new version out in
a few days.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: RLLaney@.......
To: psn-l@..............
Sent: Wednesday, March 12, 2003 3:31 PM
Subject: Winquake 2.9.4
Hi Larry:
I am having trouble emailing event files. In the Open File window, the
Send Email button is not on. Anyone else having this problem? Am I
overlooking something?
Thanks.
Bob Laney
Salem, Oregon << File: ATT00001.html >>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: New WinQuake Beta Releand and Re: Winquake 2.9.4
From: "Larry Cochrane" cochrane@..............
Date: Thu, 13 Mar 2003 01:53:13 -0800
Hi Everyone,
I have a new WinQuake beta release ready. This release fixes two bugs
reported by the beta testers. The new release (version 2.9.5B) can be
downloaded from here http://www.seismicnet.com/wqdocs/wqbeta.html. As with
the other beta release the zip file only contains a new winqk32.exe file and
a few test event files.
This release fixes the Send Email button problem and a problem with reading
GSE2.0 formatted event files.
Steve, I don't think I changed anything around the help system, so I'm not
sure why your system is not opening PSNExplorer and displaying the help
page. I removed the Save View Only check box in the File Save dialog box
since I add the Crop menu item under the View menu. If you want to Crop an
event file, first use the Crop / View menu items and then save the event
file.
Regards,
Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "steve hammond"
To:
Sent: Thursday, March 13, 2003 12:33 AM
Subject: RE: Winquake 2.9.4
> Larry, I ran into two thongs tonight with the beta release. (1) I clicked
> on help and the program quit responding and I had to cancel it via the
> close program menu. This could be MS ME. Question, help working in the
beta
> version? (2) Most important, I use this feature all the time. When saving
a
> file the save menu does not popup as it did in past releases. What
happened
> to the save only current view option?
> Thanks-- Steve Hammond
>
> -----Original Message-----
> From: Larry Cochrane [SMTP:cochrane@...............
> Sent: Wednesday, March 12, 2003 7:00 PM
> To: psn-l@..............
> Subject: Re: Winquake 2.9.4
>
> Hi Bob,
>
> This is a problem with WinQuake. I never use this feature so I didn't
> notice that the button is always grayed out. I'll have a new version out
in
> a few days.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Folded Pendulum Design
From: John or Jan Lahr johnjan@........
Date: Wed, 12 Mar 2003 22:07:23 -0700
I've added a page for Dave Youden's folded pendulum design
here:
On the weekend I'll add another page on his electronics.
This design should probably be called a "Lindenblad
folded pendulum"
as it looks like he invented it.
Cheers,
John
Subject: Lindenblad Folded Pendulum
From: John or Jan Lahr johnjan@........
Date: Thu, 13 Mar 2003 06:36:00 -0700
Below are a few words from the Scientific American Amateur Scientist article of
April, 1967. The "Complete Collection of The Amateur Scientist" is
available on
CD-ROM for $40, which is quite a bargan. See:
http://shop.store.yahoo.com/explo/amsciencdrom.html
Scientific American
by C. L. Stong
April, 1967
---------------------
........
Figure 1: Horizontal pendulum of long period devised by Nils E. Lindenblad
......
One of these is Nils E. Lindenblad of Princeton, N.J., who took up the
study of pendulums two years ago at the age of 70 after a career of 45
years as an electronics engineer. Lindenblad writes:
.....
"It is just as valid, and on occasion more helpful, to think of the period
as a function of the curvature of the arc through which the bob swings. ....
..... The linkage, as modified, consists of a horizontal bar supported at
one end by a hinged lever and suspended at the other end by a flat ribbon
of spring steel [see Figure 1]. The ribbon in turn was hinged in the middle
by means of a short length of spring stock turned at right angles to give
the suspension lateral freedom. If the ribbon and the lever are equal in
length, the midpoint on the horizontal bar will move in a straight line
when pushed along its axis through a limited distance. A bob that has a
hole through its center of gravity and is slid into position at the middle
of the bar will move as though it were suspended by a wire of infinite
length forming a pendulum of infinite period.
Cheers,
John
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Lindenblad Folded Pendulum
From: "James Hannon" jmhannon@.........
Date: Thu, 13 Mar 2003 08:09:54 -0600
---------- Original Message ----------------------------------
From: John or Jan Lahr
Reply-To: psn-l@..............
Date: Thu, 13 Mar 2003 06:36:00 -0700
The Amateur Scientist CD rom might be a little less expensive if you bought it from the source.
http://www.tinkersguild.com
>Below are a few words from the Scientific American Amateur Scientist article of
>April, 1967. The "Complete Collection of The Amateur Scientist" is
>available on
>CD-ROM for $40, which is quite a bargan. See:
>http://shop.store.yahoo.com/explo/amsciencdrom.html
>
>Scientific American
>by C. L. Stong
>April, 1967
>
>--------------------->
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Folded Pendulum
From: "David H. Youden" dyouden@.........
Date: Thu, 13 Mar 2003 09:38:40 -0500
All,
I have a hard time believing that Nils Lindenblad actually invented the
folded pendulum in 1967. I intend to do a bit of research to try to
determine whether or not he did. If anyone out there knows anything about
the history of this, or similar, devices, please let the rest of us know.
Personally, I have no objection to calling the device that I built a
"Lindenblad Seismometer", but only if he is the inventor.
Dave...
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: concrete tests
From: BOB BARNS royb1@...........
Date: Thu, 13 Mar 2003 10:07:54 -0500
Hi gang,
My information may be out of date but I was taught that the strongest
concrete is made by using the LEAST water that will make a useable mix.
Bob Barns
Gary Lindgren wrote:
>
> Scott,
> What strength are you looking for the mix you used. Was there any rock in
> the mix.
> Gary
>
> -----Original Message-----
> From: psn-l-request@..............
> [mailto:psn-l-request@................. Behalf Of beezaur
> Sent: Wednesday, March 12, 2003 4:51 PM
> To: PSN-L@..............
> Subject: concrete tests
>
> Hi all,
>
> Just an FYI in case you are interested. I will be testing the material
> properties of the 1:1 sand:cement mix used for seismometer peirs and
> sometimes as a structural member of the device itself.
>
> I will be testing cylinders in a compression test which gives elastic
> modulus and compressive strength directly. It also gives a good
> estimate of tensile strength and toughness. The plan is to test one
> batch moist cured for 28 days and one batch air cured for after 7 days
> of moist cure. Thermal properties will have to wait, as there is still
> a lot of gel in the mix at 28 days.
>
> If anyone would like to see any variations on the above, please let me
> know. I will be filling molds by 20-Mar.
>
> Scott
> --
> A day without math is like a day without sunshine.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake Beta Releand and Re: Winquake 2.9.4
From: hammond hammond@...........
Date: Thu, 13 Mar 2003 06:28:34 -0900
Larry, would you consider increasing the accuracy of the P and S arrival
times in WinQuake from tenths of seconds to hundredths of seconds? I
suspect this change has ramifications all through your software.
thanks,
Bob Hammond
Public Seismic Network - Alaska
http://apsn.awcable.com
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake Beta Releand and Re: Winquake 2.9.4
From: RLLaney@.......
Date: Thu, 13 Mar 2003 11:52:04 EST
In a message dated 3/13/03 1:53:28 AM Pacific Standard Time,
cochrane@.............. writes:
> Steve, I don't think I changed anything around the help system, so I'm not
> sure why your system is not opening PSNExplorer and displaying the help
> page.
Larry:
I have the same problem not being able to open the help page, and have had it
for some time.
Bob
In a message dated 3/13/03 1:53:28 AM Pacific Standard=
Time, cochrane@.............. writes:
Steve, I don't think I changed=20=
anything around the help system, so I'm not
sure why your system is not opening PSNExplorer and displaying the help
page.
Larry:
I have the same problem not being able to open the help page, and have had i=
t for some time.
Bob
Subject: Re: New WinQuake Beta Releand and Re: Winquake 2.9.4
From: RLLaney@.......
Date: Thu, 13 Mar 2003 12:11:31 EST
In a message dated 3/13/03 1:53:28 AM Pacific Standard Time,
cochrane@.............. writes:
> This release fixes the Send Email button problem and a problem with reading
> GSE2.0 formatted event files.
>
Larry:
The email button works fine on the new release.
Many thanks.
Bob
In a message dated 3/13/03 1:53:28 AM Pacific Standard=
Time, cochrane@.............. writes:
This release fixes the Send Ema=
il button problem and a problem with reading
GSE2.0 formatted event files.
Larry:
The email button works fine on the new release.
Many thanks.
Bob
Subject: Re: New WinQuake Beta Release
From: "Larry Cochrane" cochrane@..............
Date: Thu, 13 Mar 2003 15:33:08 -0800
Bob,
Having WinQuake display and use hundredths of a second will not improve the
accuracy of the P and S waves or the resulting information from the S-P time
difference. This is because the travel-time tables only go down to tenths of
a second. This also would require a major rewrite of WinQuake. There have
been times when I have wanted to zoom in and have an X-Scale of less then 1
second. But this don't happen very often so I have been holding off making
this change to WinQuake.
-Larry Cochrane
Redwood City, PSN
----- Original Message -----
From: "hammond"
To:
Sent: Thursday, March 13, 2003 7:28 AM
Subject: Re: New WinQuake Beta Releand and Re: Winquake 2.9.4
> Larry, would you consider increasing the accuracy of the P and S arrival
> times in WinQuake from tenths of seconds to hundredths of seconds? I
> suspect this change has ramifications all through your software.
>
> thanks,
>
> Bob Hammond
> Public Seismic Network - Alaska
> http://apsn.awcable.com
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake Beta Releand and Re: Winquake 2.9.4
From: ChrisAtUpw@.......
Date: Thu, 13 Mar 2003 19:42:53 EST
In a message dated 13/03/03, hammond@........... writes:
> Larry, would you consider increasing the accuracy of the P and S arrival
> times in WinQuake from tenths of seconds to hundredths of seconds?
Hi Bob,
Just out of interest, what is the phase delay for P & S waves on the
multipole filters that you are using?
Regards,
Chris Chapman
In a message dated 13/03/=
03, hammond@........... writes:
Larry, would you consider i=
ncreasing the accuracy of the P and S arrival=20
times in WinQuake from tenths of seconds to hundredths of seconds? =
;
Hi Bob,
Just out of interest, what is the p=
hase delay for P & S waves on the multipole filters that you are using?
Regards,
Chris Chapman
Subject: Re: New WinQuake Beta Releand and Re: Winquake 2.9.4
From: hammond hammond@...........
Date: Thu, 13 Mar 2003 17:46:52 -0900
Hi Chris,
I haven't calculated it but it looks to be from 0.1 - 0.4 seconds for the 5
Hz low pass 6-pole filter. I don't pick phase arrivals using filtered
data. Even so, your implied point is well taken. And Larry's comment is
very valid: the JB tables don't support arrivals any more accurately than
0.1 seconds.
I was thinking (always dangerous) that I would like to measure phase
arrivals as accurately as possible given that I have a very accurate GPS
clock (better than +/- 100 ms), fast digitizer in a fast PC, etc.
Bob
>Hi Bob,
>
> Just out of interest, what is the phase delay for P & S waves on
> the multipole filters that you are using?
>
> Regards,
>
> Chris Chapman
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: New WinQuake Beta Release
From: hammond hammond@...........
Date: Fri, 14 Mar 2003 07:11:35 -0900
Larry, I agree, there are times when it would be useful but nothing which
justifies rewriting Win Quake. I was just curious....
Thanks,
Bob Hammond
Public Seismic Network - Alaska
At 02:33 PM 3/13/2003, you wrote:
>Bob,
>
>Having WinQuake display and use hundredths of a second will not improve the
>accuracy of the P and S waves or the resulting information from the S-P time
>difference. This is because the travel-time tables only go down to tenths of
>a second. This also would require a major rewrite of WinQuake. There have
>been times when I have wanted to zoom in and have an X-Scale of less then 1
>second. But this don't happen very often so I have been holding off making
>this change to WinQuake.
>
>-Larry Cochrane
>Redwood City, PSN
>
>
>----- Original Message -----
>From: "hammond"
>To:
>Sent: Thursday, March 13, 2003 7:28 AM
>Subject: Re: New WinQuake Beta Releand and Re: Winquake 2.9.4
>
>
> > Larry, would you consider increasing the accuracy of the P and S arrival
> > times in WinQuake from tenths of seconds to hundredths of seconds? I
> > suspect this change has ramifications all through your software.
> >
> > thanks,
> >
> > Bob Hammond
> > Public Seismic Network - Alaska
> > http://apsn.awcable.com
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
> >
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>
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>To leave this list email PSN-L-REQUEST@.............. with
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Subject: Winquake glitch
From: "Larry Conklin" lconklin@............
Date: Fri, 14 Mar 2003 11:53:29 -0500
Hi Larry,
I've run into an odd little glitch in the file selection window in the
latest Winquake beta. If I highlight to select a contiguous subset of the
files that appear in the window and try to "Delete All", I get a program
crash. But, if I select the entire list and "Delete All" it works fine.
For what it's worth, the directory I'm working in is on my data logging
machine, which I'm accessing over a network.
Larry Conklin
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Folded Pendulum Seismometer
From: "David H. Youden" dyouden@.........
Date: Sat, 15 Mar 2003 07:18:52 -0500
Hi Chris,
Your point is well taken. I have gathered some equipment together, and
will spend some time trying to get a transfer function of the device this
weekend. Personally, I think that the motion is way too small for the air
gap between the plates to contribute much. Damping is only one effect,
however. I have seen systems where the compression of the air in the gap
causes a large enough density change to alter the dielectric constant
significantly. Anyway, lets get a transfer function and see what it looks
like.
I intend to open the loop and drive the coil with a constant current.
That means that the displacement will only decrease by four orders of
magnitude over the proposed 0.1-10 Hz test so I may have to run two
tests, each of which will cover just one octave.
If I have time, I will try the same thing with the loop closed.
Incidentally, The electronics documentation has been sent to both Larry
and John.
No, I haven't yet read "Transfer Function
of an Ultra Low Frequency Vibration Isolation System" , but I have
it on order from the school library. Should get it early next
week.
Dave...
At 06:38 PM 3/13/03 -0500, you wrote:
Hi Dave,
I have been reading through your excellent
text. Have you looked for any damping due to the capacitative sensor
plates, while in operation? This might be done by setting the pendulum
frequency to say 1 Hz, disconnecting the feedback and putting a small
step current through the force feedback coil. If there was no damping,
the system would oscillate for some time. Blair used a photodiode setup
for measuring the sensor characteristics. I use an optical differential
system on one of my sensors, but I use an under run filament bulb to give
a constant light. I get about 15 nm resolution.
The reason that I query this, is that one
limitation on the use of capacitative sensors which use changing plate
separations in air, is the gas pumping effect due to the moving plates. I
would expect a significant effect with a 2" square plate and a gap
of 10 thou. at 10 Hz. One way of reducing the problem is to drill an
array of holes in the central plate to let air flow more easily between
opposite sides of the plate. This need not greatly effect the capacity.
The damping force F = 3.n.u.A^2 / 2.Pi.x^3
for circular flat electrodes according to Jones, where n is the viscosity
of air, u is the plate velocity, A is the plate area and x is the plate
separation. The damping falls off with the cube of the plate separation
and increases with the square of the Area, which suggests two ways of
controlling any damping. The problem that I can see is that any air
damping effects will be frequency and amplitude sensitive, which could
limit the maximum seismic frequency that you can observe. I am not sure
how much the force feedback loop reduces the amplitude of the armature
with your control system.
There seem to quite a lot of test results
/ design considerations given in
"Transfer Function of an Ultra Low Frequency Vibration Isolation
System"
Jiangfeng Liu, John Winterflood and David G Blair
Rev. Sci. Instrum. 66 (5), 3216-3218, (May 1995)
I wondered if you had read it?
Regards,
Chris Chapman
Subject: Historical stuff
From: "David H. Youden" dyouden@.........
Date: Sat, 15 Mar 2003 07:39:11 -0500
All,
I have, as promised, done a little digging into the history of the folded
pendulum as a seismometer and here is what I found:
As Nils Lindenblad stated, it is a Watt's linkage, and is well known to
freshman studying mechanisms. I E-mailed Professor David Blair at The
University of Western Australia, where the device used by Lai Mun Woo was
built. Professor Blair believes that they were the first to use the
mechanism for seismographic purposes, and he states that a senior lecturer
there by the name of F. V. von Kamm was the first to suggest the
application. He goes on to note that the efforts at UWA have moved on to
Roberts Linkages and Scott- Russel linkages for their applications in
vibration isolation. Excellent papers on both applications can be found by
"Googlizing" the linkage names.
von Kamm was supposed to publish a paper on the seismograph back in 1993,
but I cannot find any evidence that he did. I will try to contact him next
week to find out what happened.
Professor Blair notes that a group in Wuhan, China has built a copy of the
folded pendulum instrument.
Note that Lindenblad specifically states that he did not build his
pendulums for seismographic purposes, as he was trying to avoid that field
of endeavor.
While web surfing, I happened across a site that I'm sure everyone else
knows about. It contains an extensive history of seismographs. Here's the
URL: http://inventors.about.com/library/inventors/biseismograph1.htm
Well, there you have it. We could call the thing:
1) Watt Seismograph
2) von Kamm Seismograph
3) UWA Seismograph
4) Anything else anyone can think up
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Historical stuff
From: John or Jan Lahr johnjan@........
Date: Sat, 15 Mar 2003 06:27:54 -0700
This is a good site for the Watt's linkage:
http://www.brockeng.com/mechanism/Watt.htm
Since this is a mechanical device not thought of by Watt as a pendulum design,
I think we should find out more about von Kamm's contribution.
Cheers,
John
At 05:39 AM 3/15/2003, you wrote:
>All,
>
>I have, as promised, done a little digging into the history of the folded
>pendulum as a seismometer and here is what I found:
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Historical stuff
From: ChrisAtUpw@.......
Date: Sat, 15 Mar 2003 19:49:19 EST
In a message dated 15/03/03, dyouden@......... writes:
> I have, as promised, done a little digging into the history of the folded
> pendulum as a seismometer and here is what I found:
>
> As Nils Lindenblad stated, it is a Watt's linkage, and is well known to
> freshman studying mechanisms. I E-mailed Professor David Blair at The
> University of Western Australia, where the device used by Lai Mun Woo was
> built. Professor Blair believes that they were the first to use the
> mechanism for seismographic purposes, and he states that a senior lecturer
> there by the name of F. V. von Kamm was the first to suggest the
>
?
> von Kamm was supposed to publish a paper on the seismograph back in 1993,
> but I cannot find any evidence that he did. I will try to contact him next
>
Good idea.
> Note that Lindenblad specifically states that he did not build his pendulums
> for seismographic purposes, as he was trying to avoid that field of
>
That is not my interpretation of Stong's text - see below.
> Well, there you have it. We could call the thing:
>
>
Watt developed steam engines and linkages for them. He had nothing to
do with pendulums or with seismometers.
>
von Kamm? There is no-one of that name at UWA and Woo gives one
reference to a F J van Kann. There is Frank van Kann Senior Lecturer, School
of Physics, Email: frank@..................
Maybe he independantly invented this construction? Woo's reference is
' (1993) - to be published' and that was in 1998.
>
They did not invent it and the credit is usually given to the inventor.
> 4) Anything else anyone can think up
Nils Lindenblad was initially trying to invent a better seismometer.
He mentions ordinary pendulum and hanging gate seismometers. Some ignoramus
told him that most of the 'problems' of seismometers had been solved and
there was just some tinkering with electronics to be done. Apparently Nils
believed this 'informant'. However, Nils describes the principles and
construction of a normal and inverted pendulum pair which can be adjusted to
give a theoretically infinite period. Quote "Scaling down my ambitions
somewhat, I set out to develop a small mechanical pendulum of good quality
and long period that could be used as a reference mass: a mass that tends to
stand still when neighboring objects move".
I have no evidence of any prior description to this type of pendulum
and specifically for this use.
Regards,
Chris Chapman
In a message dated 15/03/=
03, dyouden@......... writes:
I have, as promised, done a=
little digging into the history of the folded=20
pendulum as a seismometer and here is what I found:
As Nils Lindenblad stated, it is a Watt's linkage, and is well known to=20=
freshman studying mechanisms. I E-mailed Professor David Blair at The Univer=
sity of Western Australia, where the device used by Lai Mun Woo was built. P=
rofessor Blair believes that they were the first to use the mechanism for se=
ismographic purposes, and he states that a senior lecturer there by the name=
of F. V. von Kamm was the first to suggest the application.
?
=20
von Kamm was supposed to pu=
blish a paper on the seismograph back in 1993,=20
but I cannot find any evidence that he did. I will try to contact him ne=
xt week to find out what happened.
Good idea.
Note that Lindenblad specif=
ically states that he did not build his pendulums for seismographic purposes=
, as he was trying to avoid that field of endeavor.
That is not my interpretation of St=
ong's text - see below.
=20
Well, there you have it. We=
could call the thing:
1) Watt Seismograph
Watt developed steam engines and li=
nkages for them. He had nothing to do with pendulums or with seismometers.
2) von Kamm Seismograph
von Kamm? There is no-one of that n=
ame at UWA and Woo gives one reference to a F J van Kann. There is Frank van Kann Senior Lecturer, School of Physics, Email: frank@..................
Maybe he independantly invented thi=
s construction? Woo's reference is ' (1993) - to be published' and that was=20=
in 1998.=20
3) UWA Seismograph
They did not invent it and the cred=
it is usually given to the inventor.
4) Anything else anyone can=
think up
Nils Lindenblad was initially tryin=
g to invent a better seismometer. He mentions ordinary pendulum and hanging=20=
gate seismometers. Some ignoramus told him that most of the 'problems' of se=
ismometers had been solved and there was just some tinkering with electronic=
s to be done. Apparently Nils believed this 'informant'. However, Nils descr=
ibes the principles and construction of a normal and inverted pendulum pair=20=
which can be adjusted to give a theoretically infinite period. Quote "Scalin=
g down my ambitions somewhat, I set out to develop a small mechanical pendul=
um of good quality and long period that could be used as a reference mass: a=
mass that tends to stand still when neighboring objects move".
I have no evidence of any prior des=
cription to this type of pendulum and specifically for this use.=20
Regards,
Chris Chapman
Subject: Re: Historical stuff
From: ChrisAtUpw@.......
Date: Sat, 15 Mar 2003 19:50:56 EST
In a message dated 15/03/03, dyouden@......... writes:
> I have, as promised, done a little digging into the history of the folded
> pendulum as a seismometer and here is what I found:
>
> As Nils Lindenblad stated, it is a Watt's linkage, and is well known to
> freshman studying mechanisms. I E-mailed Professor David Blair at The
> University of Western Australia, where the device used by Lai Mun Woo was
> built. Professor Blair believes that they were the first to use the
> mechanism for seismographic purposes, and he states that a senior lecturer
> there by the name of F. V. von Kamm was the first to suggest the
>
?
> von Kamm was supposed to publish a paper on the seismograph back in 1993,
> but I cannot find any evidence that he did. I will try to contact him next
>
Good idea.
> Note that Lindenblad specifically states that he did not build his pendulums
> for seismographic purposes, as he was trying to avoid that field of
>
That is not my interpretation of Stong's text - see below.
> Well, there you have it. We could call the thing:
>
>
Watt developed steam engines and linkages for them. He had nothing to
do with pendulums or with seismometers.
>
von Kamm? There is no-one of that name at UWA and Woo gives one
reference to a F J van Kann. There is Frank van Kann Senior Lecturer, School
of Physics, Email: frank@..................
Maybe he independantly invented this construction? Woo's reference is
' (1993) - to be published' and that was in 1998.
>
They did not invent it and the credit is usually given to the inventor.
> 4) Anything else anyone can think up
Nils Lindenblad was initially trying to invent a better seismometer.
He mentions ordinary pendulum and hanging gate seismometers. Some ignoramus
told him that most of the 'problems' of seismometers had been solved and
there was just some tinkering with electronics to be done. Apparently Nils
believed this 'informant'. However, Nils describes the principles and
construction of a normal and inverted pendulum pair which can be adjusted to
give a theoretically infinite period. Quote "Scaling down my ambitions
somewhat, I set out to develop a small mechanical pendulum of good quality
and long period that could be used as a reference mass: a mass that tends to
stand still when neighboring objects move".
I have no evidence of any prior description to this type of pendulum
and specifically for this use.
Regards,
Chris Chapman
In a message dated 15/03/=
03, dyouden@......... writes:
I have, as promised, done a=
little digging into the history of the folded=20
pendulum as a seismometer and here is what I found:
As Nils Lindenblad stated, it is a Watt's linkage, and is well known to=20=
freshman studying mechanisms. I E-mailed Professor David Blair at The Univer=
sity of Western Australia, where the device used by Lai Mun Woo was built. P=
rofessor Blair believes that they were the first to use the mechanism for se=
ismographic purposes, and he states that a senior lecturer there by the name=
of F. V. von Kamm was the first to suggest the application.
?
=20
von Kamm was supposed to pu=
blish a paper on the seismograph back in 1993,=20
but I cannot find any evidence that he did. I will try to contact him ne=
xt week to find out what happened.
Good idea.
Note that Lindenblad specif=
ically states that he did not build his pendulums for seismographic purposes=
, as he was trying to avoid that field of endeavor.
That is not my interpretation of St=
ong's text - see below.
=20
Well, there you have it. We=
could call the thing:
1) Watt Seismograph
Watt developed steam engines and li=
nkages for them. He had nothing to do with pendulums or with seismometers.
2) von Kamm Seismograph
von Kamm? There is no-one of that n=
ame at UWA and Woo gives one reference to a F J van Kann. There is Frank van Kann Senior Lecturer, School of Physics, Email: frank@..................
Maybe he independantly invented thi=
s construction? Woo's reference is ' (1993) - to be published' and that was=20=
in 1998.=20
3) UWA Seismograph
They did not invent it and the cred=
it is usually given to the inventor.
4) Anything else anyone can=
think up
Nils Lindenblad was initially tryin=
g to invent a better seismometer. He mentions ordinary pendulum and hanging=20=
gate seismometers. Some ignoramus told him that most of the 'problems' of se=
ismometers had been solved and there was just some tinkering with electronic=
s to be done. Apparently Nils believed this 'informant'. However, Nils descr=
ibes the principles and construction of a normal and inverted pendulum pair=20=
which can be adjusted to give a theoretically infinite period. Quote "Scalin=
g down my ambitions somewhat, I set out to develop a small mechanical pendul=
um of good quality and long period that could be used as a reference mass: a=
mass that tends to stand still when neighboring objects move".
I have no evidence of any prior des=
cription to this type of pendulum and specifically for this use.=20
Regards,
Chris Chapman
Subject: Note of a new neodymium magnet seller
From: meredithlamb meredithlamb@.............
Date: Sun, 16 Mar 2003 00:25:48 -0700
Hi all,
If you've always been wanting a certain size very strong
gauss N45 magnet for you project, I would recommend this
seller to email write too:
jmb4447@...........
His name is John Bauer. He currently sells mostly N45 grade
magnets on E-Bay, under the handle of "thugdaddy1". His
E-Bay record thus far is unblemished, with no complaints.
The N45 grade magnets are the strongest gauss usually sold
commercially. N45 grade magnets are alittle physically
frailer than lesser grade magnets, so extra care should be
exercised in their handling.
He will commendably followup and follow through on special
order magnets sizes that are either as exactly requested, or
as near to such as possible. I have done so, and got excellent
fast response and very reasonable prices on acouple sizes I wanted,
for projects here. Both orders were for 20 pieces of each size.
Be sure to denote the polarity orientation along with size/s.
The orders take ~2-4 weeks to be made and delivered. The
magnets are were very well packed for shipment. John can
ship anywhere as long as their is a shipping company or postal
system to deliver.
John is very good to work with, and he does really want the
small quanity business. I've no affiliation with John; but it
is sure REAL nice to have a source to go to for those special
size magnets one wants.
Take care, Meredith
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Note of a new neodymium magnet seller
From: John or Jan Lahr johnjan@........
Date: Sun, 16 Mar 2003 08:50:00 -0700
Hi Meredith L. and John Bauer,
I've added Meredith's message to my "sources of magnets" page:
http://jjlahr.com/science/physics/bauer.html
Let me know if that's OK with both of you. And, John, thanks
for the excellent service you've provided to Meredith. I hope you
are very successful with you business, as there is a lot of
interest in strong magnets by the amateur scientist community.
Cheers,
John
At 12:25 AM 3/16/2003, you wrote:
>Hi all,
>
>If you've always been wanting a certain size very strong
>gauss N45 magnet for you project, I would recommend this
>seller to email write too:
>
>jmb4447@...........
>
>His name is John Bauer. He currently sells mostly N45 grade
>magnets on E-Bay, under the handle of "thugdaddy1". His
>E-Bay record thus far is unblemished, with no complaints.
>
>The N45 grade magnets are the strongest gauss usually sold
>commercially. N45 grade magnets are alittle physically
>frailer than lesser grade magnets, so extra care should be
>exercised in their handling.
>
>He will commendably followup and follow through on special
>order magnets sizes that are either as exactly requested, or
>as near to such as possible. I have done so, and got excellent
>fast response and very reasonable prices on acouple sizes I wanted,
>for projects here. Both orders were for 20 pieces of each size.
>Be sure to denote the polarity orientation along with size/s.
>
>The orders take ~2-4 weeks to be made and delivered. The
>magnets are were very well packed for shipment. John can
>ship anywhere as long as their is a shipping company or postal
>system to deliver.
>
>John is very good to work with, and he does really want the
>small quanity business. I've no affiliation with John; but it
>is sure REAL nice to have a source to go to for those special
>size magnets one wants.
>
>Take care, Meredith
>
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re:Historical stuff
From: "David H. Youden" dyouden@.........
Date: Sun, 16 Mar 2003 11:28:17 -0500
All,
I have e-mailed Frank van Kann. Sorry about the mis-spelling. That's what I
get from posting this stuff early in the morning and trying to remember
what I was thinking about the night before.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Tests on folded pendulum instrument
From: "David H. Youden" dyouden@.........
Date: Sun, 16 Mar 2003 11:57:47 -0500
All,
I got a chance yesterday to run some tests on my instrument.
Here's what I did:
I opened the loop and drove the force balance coil directly with a HP
function generator ( Model 3310B). I placed a 1000 ohm resistor in series
with the coil. I took my input signal from across the coil so I had a
sensitivity of 1000 volts/amp. The output was taken at the output of the
cap gauge circuit, after a 2 pole 35 Hz filter that would have been
inconvenient to remove. The output device was a HP 54603B memory scope. The
driven mass is pretty close to 500 grams.
I attempted to take phase and P-P position data at constant acceleration
from 0.1 Hz to 10 Hz while holding the current through the coil at 94
microamps, i. e. 94 millivolts across 1000 ohms. Why that value? Because it
was the maximum that I could use at 0.1 Hz and still maintain linearity of
the cap gauge signal.
Results:
The force balance coil/magnet combination have a transfer function of 0.26
Newtons/Amp.
I lost the signal in the noise at about 6 Hz. Obviously, I could go higher
with a larger input signal.
The phase between acceleration and displacement was less than 20 degrees
throughout the range.
The P-P displacement was about 60 nanometers at 6 Hz.
The laws of physics still apply, as the P-P position signal was inversely
proportional to the square of the frequency.
There was no sign of roll-off due to damping from the cap gauge, but then
the amplitudes were pretty low at the higher frequencies.
Comment: My low pass filters are set to roll off at 5 Hz so data beyond
that point is academic.
Dave ...
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Tests on folded pendulum instrument
From: Jim ODonnell jimo17@........
Date: Sun, 16 Mar 2003 09:59:37 -0800
Hi Dave- You got my attention- Nice work!- Do you have any records
(seismograms) posted that we can look at?
Jim O'Donnell - UNLV
On Sun, 16 Mar 2003 11:57:47 -0500 "David H. Youden"
writes:
> All,
>
> I got a chance yesterday to run some tests on my instrument.
>
> Here's what I did:
>
> I opened the loop and drove the force balance coil directly with a
> HP
> function generator ( Model 3310B). I placed a 1000 ohm resistor in
> series
> with the coil. I took my input signal from across the coil so I had
> a
> sensitivity of 1000 volts/amp. The output was taken at the output of
> the
> cap gauge circuit, after a 2 pole 35 Hz filter that would have been
>
> inconvenient to remove. The output device was a HP 54603B memory
> scope. The
> driven mass is pretty close to 500 grams.
>
> I attempted to take phase and P-P position data at constant
> acceleration
> from 0.1 Hz to 10 Hz while holding the current through the coil at
> 94
> microamps, i. e. 94 millivolts across 1000 ohms. Why that value?
> Because it
> was the maximum that I could use at 0.1 Hz and still maintain
> linearity of
> the cap gauge signal.
>
> Results:
>
> The force balance coil/magnet combination have a transfer function
> of 0.26
> Newtons/Amp.
>
> I lost the signal in the noise at about 6 Hz. Obviously, I could go
> higher
> with a larger input signal.
>
> The phase between acceleration and displacement was less than 20
> degrees
> throughout the range.
>
> The P-P displacement was about 60 nanometers at 6 Hz.
>
> The laws of physics still apply, as the P-P position signal was
> inversely
> proportional to the square of the frequency.
>
> There was no sign of roll-off due to damping from the cap gauge, but
> then
> the amplitudes were pretty low at the higher frequencies.
>
> Comment: My low pass filters are set to roll off at 5 Hz so data
> beyond
> that point is academic.
>
> Dave ...
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
>
________________________________________________________________
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__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Folded Pendulum seismometer
From: John or Jan Lahr johnjan@........
Date: Sun, 16 Mar 2003 21:19:05 -0700
Hi Chris and others interested in David Youden's folded pendulum
design. I've just added
his documentation here: http://jjlahr.com/science/psn/youden/electronics/fpelectronics.html
Cheers,
John
At 01:35 PM 3/16/2003, Chris wrote:
Have you
received a circuit diagram from Dave Youden yet? I will be very
interested to see it.
Subject: Re: Tests on folded pendulum instrument
From: "David H. Youden" dyouden@.........
Date: Mon, 17 Mar 2003 06:06:04 -0500
Jim,
I use Dataq"s Windaq software for a variety of reasons, so my recordings
are not compatible with the more common formats. I do have a few, which I
would be happy to share with anyone who can handle the file format, or I
can make picture files of them in some common format e. g. GIF or JPG.
Dave...
At 09:59 AM 3/16/03 -0800, you wrote:
>Hi Dave- You got my attention- Nice work!- Do you have any records
>(seismograms) posted that we can look at?
>Jim O'Donnell - UNLV
>On Sun, 16 Mar 2003 11:57:47 -0500 "David H. Youden"
>writes:
> > All,
> >
> > I got a chance yesterday to run some tests on my instrument.
> >
> > Here's what I did:
> >
> > I opened the loop and drove the force balance coil directly with a
> > HP
> > function generator ( Model 3310B). I placed a 1000 ohm resistor in
> > series
> > with the coil. I took my input signal from across the coil so I had
> > a
> > sensitivity of 1000 volts/amp. The output was taken at the output of
> > the
> > cap gauge circuit, after a 2 pole 35 Hz filter that would have been
> >
> > inconvenient to remove. The output device was a HP 54603B memory
> > scope. The
> > driven mass is pretty close to 500 grams.
> >
> > I attempted to take phase and P-P position data at constant
> > acceleration
> > from 0.1 Hz to 10 Hz while holding the current through the coil at
> > 94
> > microamps, i. e. 94 millivolts across 1000 ohms. Why that value?
> > Because it
> > was the maximum that I could use at 0.1 Hz and still maintain
> > linearity of
> > the cap gauge signal.
> >
> > Results:
> >
> > The force balance coil/magnet combination have a transfer function
> > of 0.26
> > Newtons/Amp.
> >
> > I lost the signal in the noise at about 6 Hz. Obviously, I could go
> > higher
> > with a larger input signal.
> >
> > The phase between acceleration and displacement was less than 20
> > degrees
> > throughout the range.
> >
> > The P-P displacement was about 60 nanometers at 6 Hz.
> >
> > The laws of physics still apply, as the P-P position signal was
> > inversely
> > proportional to the square of the frequency.
> >
> > There was no sign of roll-off due to damping from the cap gauge, but
> > then
> > the amplitudes were pretty low at the higher frequencies.
> >
> > Comment: My low pass filters are set to roll off at 5 Hz so data
> > beyond
> > that point is academic.
> >
> > Dave ...
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
> >
> >
>
>________________________________________________________________
>Sign Up for Juno Platinum Internet Access Today
>Only $9.95 per month!
>Visit www.juno.com
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Tests on folded pendulum instrument
From: Jim ODonnell jimo17@........
Date: Mon, 17 Mar 2003 06:07:26 -0800
Hi Dave- I use DataQ poducts and WinDaq on occassion for K-12 school
seismographs in Las Vegas- like the DI-194 (10 bit A/D for $25).
If you can send me some data of events I would love to look at it.
Send it to:
jimo17@........
Thanks....Jim
On Mon, 17 Mar 2003 06:06:04 -0500 "David H. Youden"
writes:
> Jim,
>
> I use Dataq"s Windaq software for a variety of reasons, so my
> recordings
> are not compatible with the more common formats. I do have a few,
> which I
> would be happy to share with anyone who can handle the file format,
> or I
> can make picture files of them in some common format e. g. GIF or
> JPG.
>
> Dave...
>
> At 09:59 AM 3/16/03 -0800, you wrote:
> >Hi Dave- You got my attention- Nice work!- Do you have any
> records
> >(seismograms) posted that we can look at?
> >Jim O'Donnell - UNLV
> >On Sun, 16 Mar 2003 11:57:47 -0500 "David H. Youden"
>
> >writes:
> > > All,
> > >
> > > I got a chance yesterday to run some tests on my instrument.
> > >
> > > Here's what I did:
> > >
> > > I opened the loop and drove the force balance coil directly with
> a
> > > HP
> > > function generator ( Model 3310B). I placed a 1000 ohm resistor
> in
> > > series
> > > with the coil. I took my input signal from across the coil so I
> had
> > > a
> > > sensitivity of 1000 volts/amp. The output was taken at the
> output of
> > > the
> > > cap gauge circuit, after a 2 pole 35 Hz filter that would have
> been
> > >
> > > inconvenient to remove. The output device was a HP 54603B
> memory
> > > scope. The
> > > driven mass is pretty close to 500 grams.
> > >
> > > I attempted to take phase and P-P position data at constant
> > > acceleration
> > > from 0.1 Hz to 10 Hz while holding the current through the coil
> at
> > > 94
> > > microamps, i. e. 94 millivolts across 1000 ohms. Why that
> value?
> > > Because it
> > > was the maximum that I could use at 0.1 Hz and still maintain
> > > linearity of
> > > the cap gauge signal.
> > >
> > > Results:
> > >
> > > The force balance coil/magnet combination have a transfer
> function
> > > of 0.26
> > > Newtons/Amp.
> > >
> > > I lost the signal in the noise at about 6 Hz. Obviously, I could
> go
> > > higher
> > with a larger input signal.
> > >
> > > The phase between acceleration and displacement was less than
> 20
> > > degrees
> > > throughout the range.
> > >
> > > The P-P displacement was about 60 nanometers at 6 Hz.
> > >
> > > The laws of physics still apply, as the P-P position signal was
> > > inversely
> > > proportional to the square of the frequency.
> > >
> > > There was no sign of roll-off due to damping from the cap gauge,
> but
> > > then
> > > the amplitudes were pretty low at the higher frequencies.
> > >
> > > Comment: My low pass filters are set to roll off at 5 Hz so
> data
> > > beyond
> > > that point is academic.
> > >
> > > Dave ...
> > >
> > > __________________________________________________________
> > >
> > > Public Seismic Network Mailing List (PSN-L)
> > >
> > > To leave this list email PSN-L-REQUEST@.............. with
> > > the body of the message (first line only): unsubscribe
> > > See http://www.seismicnet.com/maillist.html for more
> information.
> > >
> > >
> >
> >________________________________________________________________
> >Sign Up for Juno Platinum Internet Access Today
> >Only $9.95 per month!
> >Visit www.juno.com
> >__________________________________________________________
> >
> >Public Seismic Network Mailing List (PSN-L)
> >
> >To leave this list email PSN-L-REQUEST@.............. with
> >the body of the message (first line only): unsubscribe
> >See http://www.seismicnet.com/maillist.html for more information.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
>
>
________________________________________________________________
Sign Up for Juno Platinum Internet Access Today
Only $9.95 per month!
Visit www.juno.com
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Tests on folded pendulum instrument
From: Stephen & Kathy skmort@..........
Date: Mon, 17 Mar 2003 11:13:01 -0800
Hi David,, If your interested in converting your files to PSN format, you might
try John Lahr's WDQ2PSN converter program,,, I use it with my Dataq DI-150RS
and it works great!! You might ask John if it will work on your files???
Hopefully, they are the same format????
You can find it at:
http://jjlahr.com/science/psn/gldn_psn.html
Scroll down to the middle of the page to find his info and the link to the
program!
If yours are the same format and you decide to try it and have problems or
questions, I'll be glad to try and help,,,, or if you would like to send a few
minute of a recording, I'll try to convert it and let you know how or if it
works!!! If your interested in seeing one of my traces converted to PSN format
and then converted to a gif using the WINQUAKE program, you can see it on Bob
Shannon's web site,, (it is the recording of the 4.0 Mammoth Lakes quake a few
days back), when you get there click on TRACES,, at:
http://www.televar.com/~earth/alert.html
Stephen
PSN Station #55
near Pilot Hill Ca
38.828N 120.979W
"David H. Youden" wrote:
>
> Jim,
>
> I use Dataq"s Windaq software for a variety of reasons, so my recordings
> are not compatible with the more common formats. I do have a few, which I
> would be happy to share with anyone who can handle the file format, or I
> can make picture files of them in some common format e. g. GIF or JPG.
>
> Dave...
>
> At 09:59 AM 3/16/03 -0800, you wrote:
> >Hi Dave- You got my attention- Nice work!- Do you have any records
> >(seismograms) posted that we can look at?
> >Jim O'Donnell - UNLV
> >On Sun, 16 Mar 2003 11:57:47 -0500 "David H. Youden"
> >writes:
> > > All,
> > >
> > > I got a chance yesterday to run some tests on my instrument.
> > >
> > > Here's what I did:
> > >
> > > I opened the loop and drove the force balance coil directly with a
> > > HP
> > > function generator ( Model 3310B). I placed a 1000 ohm resistor in
> > > series
> > > with the coil. I took my input signal from across the coil so I had
> > > a
> > > sensitivity of 1000 volts/amp. The output was taken at the output of
> > > the
> > > cap gauge circuit, after a 2 pole 35 Hz filter that would have been
> > >
> > > inconvenient to remove. The output device was a HP 54603B memory
> > > scope. The
> > > driven mass is pretty close to 500 grams.
> > >
> > > I attempted to take phase and P-P position data at constant
> > > acceleration
> > > from 0.1 Hz to 10 Hz while holding the current through the coil at
> > > 94
> > > microamps, i. e. 94 millivolts across 1000 ohms. Why that value?
> > > Because it
> > > was the maximum that I could use at 0.1 Hz and still maintain
> > > linearity of
> > > the cap gauge signal.
> > >
> > > Results:
> > >
> > > The force balance coil/magnet combination have a transfer function
> > > of 0.26
> > > Newtons/Amp.
> > >
> > > I lost the signal in the noise at about 6 Hz. Obviously, I could go
> > > higher
> > > with a larger input signal.
> > >
> > > The phase between acceleration and displacement was less than 20
> > > degrees
> > > throughout the range.
> > >
> > > The P-P displacement was about 60 nanometers at 6 Hz.
> > >
> > > The laws of physics still apply, as the P-P position signal was
> > > inversely
> > > proportional to the square of the frequency.
> > >
> > > There was no sign of roll-off due to damping from the cap gauge, but
> > > then
> > > the amplitudes were pretty low at the higher frequencies.
> > >
> > > Comment: My low pass filters are set to roll off at 5 Hz so data
> > > beyond
> > > that point is academic.
> > >
> > > Dave ...
> > >
> > > __________________________________________________________
> > >
> > > Public Seismic Network Mailing List (PSN-L)
> > >
> > > To leave this list email PSN-L-REQUEST@.............. with
> > > the body of the message (first line only): unsubscribe
> > > See http://www.seismicnet.com/maillist.html for more information.
> > >
> > >
> >
> >________________________________________________________________
> >Sign Up for Juno Platinum Internet Access Today
> >Only $9.95 per month!
> >Visit www.juno.com
> >__________________________________________________________
> >
> >Public Seismic Network Mailing List (PSN-L)
> >
> >To leave this list email PSN-L-REQUEST@.............. with
> >the body of the message (first line only): unsubscribe
> >See http://www.seismicnet.com/maillist.html for more information.
>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with
> the body of the message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Tests on folded pendulum instrument
From: ChrisAtUpw@.......
Date: Mon, 17 Mar 2003 23:59:50 EST
In a message dated 16/03/03, dyouden@......... writes:
> I got a chance yesterday to run some tests on my instrument.
> Here's what I did:
>
> I opened the loop and drove the force balance coil directly with a HP
> function generator ( Model 3310B). I placed a 1000 ohm resistor in series
> with the coil. I took my input signal from across the coil so I had a
> sensitivity of 1000 volts/amp. The output was taken at the output of the
> cap gauge circuit, after a 2 pole 35 Hz filter that would have been
> inconvenient to remove. The output device was a HP 54603B memory scope. The
> driven mass is pretty close to 500 grams.
>
> I attempted to take phase and P-P position data at constant acceleration
> from 0.1 Hz to 10 Hz while holding the current through the coil at 94
> microamps, i. e. 94 millivolts across 1000 ohms. Why that value? Because it
> was the maximum that I could use at 0.1 Hz and still maintain linearity of
> the cap gauge signal.
>
> Results:
> The force balance coil/magnet combination have a transfer function of 0.26
>
Hi Dave,
It should be possible to increase this force without too much
difficulty using a soft iron rectangular chamber to enclose the magnet and
the coil. This would also make the force nearly independant of the coil
position. Other PSN equipment has attained 10 to >30 N/A.
> I lost the signal in the noise at about 6 Hz. Obviously, I could go higher
> with a larger input signal.
>
> The phase between acceleration and displacement was less than 20 degrees
> throughout the range.
> The P-P displacement was about 60 nanometers at 6 Hz.
>
> The laws of physics still apply, as the P-P position signal was inversely
> proportional to the square of the frequency. There was no sign of roll-off
> due to damping from the cap gauge, but then the amplitudes were pretty low
> at the higher frequencies.
>
> Comment: My low pass filters are set to roll off at 5 Hz so data beyond
> that point is academic.
Measuring any damping due to the capacitative sensor plates in
operation might be done by setting the pendulum frequency to say 1 Hz,
disconnecting the feedback and putting a small step current through the force
feedback coil. If there is no damping, the system would oscillate for some
time. Dr.Blair used a photodiode setup for measuring the sensor
characteristics.
The reason that I query this, is that one limitation on the use of
capacitative sensors which use changing plate separations in air, is the gas
pumping effect due to the moving plates. I would expect a significant effect
with a 2" square plate and a gap of 10 thou. at 10 Hz. One way of reducing
the problem is to drill an array of holes in the central plate to let air
flow more easily between opposite sides of the plate. This need not greatly
effect the capacity.
The damping force F = 3.n.u.A^2 / 2.Pi.x^3 for circular flat electrodes
according to Jones, where n is the viscosity of air, u is the plate velocity,
A is the plate area and x is the plate separation. The damping falls off with
the cube of the plate separation and increases with the square of the Area,
which suggests two ways of controlling any damping. The problem that I can
see is that any air damping effects will be frequency and amplitude
sensitive, which could limit the maximum seismic frequency that you can
observe.
Your force feedback loop should dramatically reduce the amplitude of
the armature swings and keep the mass nearly still.
Just adding critical damping to the response still allows quite large
amplitude movements.
What period is the pendulum set at?
How did you determine the calibration and linear range of your
capacitor sensor? What sensitivity and linear range do you get? The +/-250
micron max possible movement range, with maybe only a fraction of this giving
a linear output, may be a bit restricting.
You might try using nylon monofilament fishing line as a spacer for
setting the capacitor gaps.
A rough calculation of the bridge suggests that the output becomes non
linear for any movement greater than 1/3 of the gap. A bridge circuit may not
be the most sensitive and linear option. Jones just used a charge amplifier
in your reference. Linear Technology have several capacitance measuring
circuits in their application notes.
What amplitude do you measure for the 6 second ocean microseisms?
I would not expect the test you describe to show significant damping.
The damping force due to the air gaps depends on the velocity of the plate
and this will be very low for micron movements and low frequencies. Real
quakes could be a lot larger.
This is why I suggested that you put a small DC current through the
coil to deflect the arm and then track the deflection to measure the
decrement of any oscillations. Maybe using your A/D and Winquake?
Some notes on the Circuit.
The back to back diodes will not give a very stable oscillator
amplitude over a wide temperature range. An XR8038 sine wave generator IC
might be better and simpler, particularly if you add a two pole output
filter. Circuits for very high stability Wein bridge oscillators are
available and there are several other options.
The INA121 is right at it's frequency limit at a gain of 100 at 50
KHz. It's CMRR is only ~65 dB at this frequency. You might consider the high
speed INA111?
You might get improved results and less noise if you used an OP07 or a
trimmed TL071 for the signal inverter U7A.
Low noise analogue switches are available.
For the lead/direct circuit, you can feed the signal into the
inverting input with a R and a CR in parallel to separate out the two
components. An OPA604 low noise fet amplifier will give about 40 mA max and
could replace the OPA551.
The integrator has a time constant of about 1 sec. You might wish to
increase this to cover the lower part of the frequency range. If you take the
output from the input to the feedback circuit, don't you get a velocity
response without using an integrator?
http://www.geophys.uni-stuttgart.de/seismometry/hbk_html/node24.html
Hope that this is of some interest / help.
Regards,
Chris Chapman
In a message dated 16/03/=
03, dyouden@......... writes:
I got a chance yesterday to=
run some tests on my instrument.
Here's what I did:
I opened the loop and drove the force balance coil directly with a HP fu=
nction generator ( Model 3310B). I placed a 1000 ohm resistor in series with=
the coil. I took my input signal from across the coil so I had a sensitivit=
y of 1000 volts/amp. The output was taken at the output of the cap gauge cir=
cuit, after a 2 pole 35 Hz filter that would have been inconvenient to remov=
e. The output device was a HP 54603B memory scope. The driven mass is pretty=
close to 500 grams.
I attempted to take phase and P-P position data at constant acceleration=
from 0.1 Hz to 10 Hz while holding the current through the coil at 94 micro=
amps, i. e. 94 millivolts across 1000 ohms. Why that value? Because it was t=
he maximum that I could use at 0.1 Hz and still maintain linearity of the ca=
p gauge signal.
Results:
The force balance coil/magnet combination have a transfer function of 0.=
26=20
Newtons/Amp.
Hi Dave,=20
It should be possible to increase t=
his force without too much difficulty using a soft iron rectangular chamber=20=
to enclose the magnet and the coil. This would also make the force nearly in=
dependant of the coil position. Other PSN equipment has attained 10 to >3=
0 N/A.=20
I lost the signal in the no=
ise at about 6 Hz. Obviously, I could go higher with a larger input signal.
The phase between acceleration and displacement was less than 20 degrees=
=20
throughout the range.
The P-P displacement was about 60 nanometers at 6 Hz.
The laws of physics still apply, as the P-P position signal was inversel=
y proportional to the square of the frequency. There was no sign of roll-off=
due to damping from the cap gauge, but then the amplitudes were pretty low=20=
at the higher frequencies.
Comment: My low pass filters are set to roll off at 5 Hz so data beyond=20=
that point is academic.
Measuring any damping due to the ca=
pacitative sensor plates in operation might be done by setting the pendulum=20=
frequency to say 1 Hz, disconnecting the feedback and putting a small step c=
urrent through the force feedback coil. If there is no damping, the system w=
ould oscillate for some time. Dr.Blair used a photodiode setup for measuring=
the sensor characteristics.=20
The reason that I query this, is that one=
limitation on the use of capacitative sensors which use changing plate sepa=
rations in air, is the gas pumping effect due to the moving plates. I would=20=
expect a significant effect with a 2" square plate and a gap of 10 thou. at=20=
10 Hz. One way of reducing the problem is to drill an array of holes in the=20=
central plate to let air flow more easily between opposite sides of the plat=
e. This need not greatly effect the capacity.=20
The damping force F =3D 3.n.u.A^2 / 2.Pi.=
x^3 for circular flat electrodes according to Jones, where n is the viscosit=
y of air, u is the plate velocity, A is the plate area and x is the plate se=
paration. The damping falls off with the cube of the plate separation and in=
creases with the square of the Area, which suggests two ways of controlling=20=
any damping. The problem that I can see is that any air damping effects will=
be frequency and amplitude sensitive, which could limit the maximum seismic=
frequency that you can observe.=20
Your force feedback loop should dra=
matically reduce the amplitude of the armature swings and keep the mass near=
ly still.=20
Just adding critical damping to the=
response still allows quite large amplitude movements.
What period is the pendulum set at?
How did you determine the calibrati=
on and linear range of your capacitor sensor? What sensitivity and linear ra=
nge do you get? The +/-250 micron max possible movement range, with maybe on=
ly a fraction of this giving a linear output, may be a bit restricting.
You might try using nylon monofilam=
ent fishing line as a spacer for setting the capacitor gaps.
A rough calculation of the bridge s=
uggests that the output becomes non linear for any movement greater than 1/3=
of the gap. A bridge circuit may not be the most sensitive and linear optio=
n. Jones just used a charge amplifier in your reference. Linear Technology h=
ave several capacitance measuring circuits in their application notes.
What amplitude do you measure for t=
he 6 second ocean microseisms?
I would not expect the test you des=
cribe to show significant damping. The damping force due to the air gaps dep=
ends on the velocity of the plate and this will be very low for micron movem=
ents and low frequencies. Real quakes could be a lot larger.
This is why I suggested that you pu=
t a small DC current through the coil to deflect the arm and then track the=20=
deflection to measure the decrement of any oscillations. Maybe using your A/=
D and Winquake?
Some notes on the Circuit.
The back to back diodes will not gi=
ve a very stable oscillator amplitude over a wide temperature range. An XR80=
38 sine wave generator IC might be better and simpler, particularly if you a=
dd a two pole output filter. Circuits for very high stability Wein bridge os=
cillators are available and there are several other options.
The INA121 is right at it's frequen=
cy limit at a gain of 100 at 50 KHz. It's CMRR is only ~65 dB at this freque=
ncy. You might consider the high speed INA111?
You might get improved results and=20=
less noise if you used an OP07 or a trimmed TL071 for the signal inverter U7=
A.
Low noise analogue switches are ava=
ilable.
For the lead/direct circuit, you ca=
n feed the signal into the inverting input with a R and a CR in parallel to=20=
separate out the two components. An OPA604 low noise fet amplifier will give=
about 40 mA max and could replace the OPA551.
The integrator has a time constant=20=
of about 1 sec. You might wish to increase this to cover the lower part of t=
he frequency range. If you take the output from the input to the feedback ci=
rcuit, don't you get a velocity response without using an integrator? http:/=
/www.geophys.uni-stuttgart.de/seismometry/hbk_html/node24.html
Hope that this is of some interest=20=
/ help.
Regards,
Chris Chapman
Subject: Fwd: Re: Event file conversion
From: John or Jan Lahr johnjan@........
Date: Tue, 18 Mar 2003 08:34:46 -0700
Date: Tue, 18 Mar 2003 07:27:46
-0700
To: Bobhelenmcclure@.......
From: John or Jan Lahr <johnjan@........>
Subject: Re: Event file conversion
Hi Bob,
Thanks for making your WinDaq to PSN4 conversion program available at
this time, because I think there is
quite a bit of interest. I put the program here: http://jjlahr.com/science/psn/mcclure/dataq2psn/
You can always send updated versions if you make changes in the
future.
Cheers,
John
At 09:09 PM 3/17/2003, you wrote:
Hi John,
The Rat Island M6.8 event file is attached. Note that the P
wave excites 0.7 Hz vibrations. I see that frequency all the
time. I get the idea that the subsurface locally is like a bowl of
Jell-O which has a natural frequency of 0.7 Hz. The vertical
seismometer shows much less response to this "vibration".
I live on terminal moraine, between two bays. Bedrock is about 300
feet down. The LDEO Palisades site doesn't seem to have this
problem. They are close to, if not on, bedrock. You know
better than I do about that.
As the day has worn on, I have tested all the functions of
HeadpikV2, and everything seems to work, so I am attaching a zip file
containing the exe, the source code, the operating instructions, and
today's event files (both the WDQ and PSN formats). I am surely
pleased that now I can use all the features and universality of WinQuake,
and still stick to recording and period-extending filtering with my Dataq
devices and software. I may eventually add an "ini" file
to the program, where the use can enter his coordinates, the input
direction for each channel, channel name, sensor name, and sensor
properties, so that all that doesn't have to be hand-entered everytime
one wants to create a Winquake file. In fact, it is set up for
velocity data, and the user of this program can't change that without
modifying the source code. An "ini" file could overcome
that handicap, as well as some others.
Regards,
Bob
Subject: Re: Tests on folded pendulum instrument
From: "David H. Youden" dyouden@.........
Date: Tue, 18 Mar 2003 17:17:55 -0500
Jim,
I found out that I can convert these files to PSN type 4 files. Is that OK
with you?. If so, I will send in a day or two. I've got a couple of buzy
days coming up.
Dave...
At 06:07 AM 3/17/03 -0800, you wrote:
>Hi Dave- I use DataQ poducts and WinDaq on occassion for K-12 school
>seismographs in Las Vegas- like the DI-194 (10 bit A/D for $25).
>If you can send me some data of events I would love to look at it.
>Send it to:
>jimo17@........
>
>Thanks....Jim
>On Mon, 17 Mar 2003 06:06:04 -0500 "David H. Youden"
>writes:
> > Jim,
> >
> > I use Dataq"s Windaq software for a variety of reasons, so my
> > recordings
> > are not compatible with the more common formats. I do have a few,
> > which I
> > would be happy to share with anyone who can handle the file format,
> > or I
> > can make picture files of them in some common format e. g. GIF or
> > JPG.
> >
> > Dave...
> >
> > At 09:59 AM 3/16/03 -0800, you wrote:
> > >Hi Dave- You got my attention- Nice work!- Do you have any
> > records
> > >(seismograms) posted that we can look at?
> > >Jim O'Donnell - UNLV
> > >On Sun, 16 Mar 2003 11:57:47 -0500 "David H. Youden"
> >
> > >writes:
> > > > All,
> > > >
> > > > I got a chance yesterday to run some tests on my instrument.
> > > >
> > > > Here's what I did:
> > > >
> > > > I opened the loop and drove the force balance coil directly with
> > a
> > > > HP
> > > > function generator ( Model 3310B). I placed a 1000 ohm resistor
> > in
> > > > series
> > > > with the coil. I took my input signal from across the coil so I
> > had
> > > > a
> > > > sensitivity of 1000 volts/amp. The output was taken at the
> > output of
> > > > the
> > > > cap gauge circuit, after a 2 pole 35 Hz filter that would have
> > been
> > > >
> > > > inconvenient to remove. The output device was a HP 54603B
> > memory
> > > > scope. The
> > > > driven mass is pretty close to 500 grams.
> > > >
> > > > I attempted to take phase and P-P position data at constant
> > > > acceleration
> > > > from 0.1 Hz to 10 Hz while holding the current through the coil
> > at
> > > > 94
> > > > microamps, i. e. 94 millivolts across 1000 ohms. Why that
> > value?
> > > > Because it
> > > > was the maximum that I could use at 0.1 Hz and still maintain
> > > > linearity of
> > > > the cap gauge signal.
> > > >
> > > > Results:
> > > >
> > > > The force balance coil/magnet combination have a transfer
> > function
> > > > of 0.26
> > > > Newtons/Amp.
> > > >
> > > > I lost the signal in the noise at about 6 Hz. Obviously, I could
> > go
> > > > higher
> > > with a larger input signal.
> > > >
> > > > The phase between acceleration and displacement was less than
> > 20
> > > > degrees
> > > > throughout the range.
> > > >
> > > > The P-P displacement was about 60 nanometers at 6 Hz.
> > > >
> > > > The laws of physics still apply, as the P-P position signal was
> > > > inversely
> > > > proportional to the square of the frequency.
> > > >
> > > > There was no sign of roll-off due to damping from the cap gauge,
> > but
> > > > then
> > > > the amplitudes were pretty low at the higher frequencies.
> > > >
> > > > Comment: My low pass filters are set to roll off at 5 Hz so
> > data
> > > > beyond
> > > > that point is academic.
> > > >
> > > > Dave ...
> > > >
> > > > __________________________________________________________
> > > >
> > > > Public Seismic Network Mailing List (PSN-L)
> > > >
> > > > To leave this list email PSN-L-REQUEST@.............. with
> > > > the body of the message (first line only): unsubscribe
> > > > See http://www.seismicnet.com/maillist.html for more
> > information.
> > > >
> > > >
> > >
> > >________________________________________________________________
> > >Sign Up for Juno Platinum Internet Access Today
> > >Only $9.95 per month!
> > >Visit www.juno.com
> > >__________________________________________________________
> > >
> > >Public Seismic Network Mailing List (PSN-L)
> > >
> > >To leave this list email PSN-L-REQUEST@.............. with
> > >the body of the message (first line only): unsubscribe
> > >See http://www.seismicnet.com/maillist.html for more information.
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
> >
> >
>
>________________________________________________________________
>Sign Up for Juno Platinum Internet Access Today
>Only $9.95 per month!
>Visit www.juno.com
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
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>the body of the message (first line only): unsubscribe
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__________________________________________________________
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Subject: Re: Tests on folded pendulum instrument
From: "David H. Youden" dyouden@.........
Date: Tue, 18 Mar 2003 17:19:31 -0500
Stephen,
Thanks for the tip. It seems to work just fine. I'll send you a couple of
the converted files in a day or two.
Dave...
At 11:13 AM 3/17/03 -0800, you wrote:
>Hi David,, If your interested in converting your files to PSN format, you
>might
>try John Lahr's WDQ2PSN converter program,,, I use it with my Dataq DI-150RS
>and it works great!! You might ask John if it will work on your files???
>Hopefully, they are the same format????
>You can find it at:
>
>http://jjlahr.com/science/psn/gldn_psn.html
>
>Scroll down to the middle of the page to find his info and the link to the
>program!
>If yours are the same format and you decide to try it and have problems or
>questions, I'll be glad to try and help,,,, or if you would like to send
>a few
>minute of a recording, I'll try to convert it and let you know how or if it
>works!!! If your interested in seeing one of my traces converted to PSN
>format
>and then converted to a gif using the WINQUAKE program, you can see it on Bob
>Shannon's web site,, (it is the recording of the 4.0 Mammoth Lakes quake a few
>days back), when you get there click on TRACES,, at:
>
>http://www.televar.com/~earth/alert.html
>
> Stephen
> PSN Station #55
> near Pilot Hill Ca
> 38.828N 120.979W
>
>"David H. Youden" wrote:
> >
> > Jim,
> >
> > I use Dataq"s Windaq software for a variety of reasons, so my recordings
> > are not compatible with the more common formats. I do have a few, which I
> > would be happy to share with anyone who can handle the file format, or I
> > can make picture files of them in some common format e. g. GIF or JPG.
> >
> > Dave...
> >
> > At 09:59 AM 3/16/03 -0800, you wrote:
> > >Hi Dave- You got my attention- Nice work!- Do you have any records
> > >(seismograms) posted that we can look at?
> > >Jim O'Donnell - UNLV
> > >On Sun, 16 Mar 2003 11:57:47 -0500 "David H. Youden"
> > >writes:
> > > > All,
> > > >
> > > > I got a chance yesterday to run some tests on my instrument.
> > > >
> > > > Here's what I did:
> > > >
> > > > I opened the loop and drove the force balance coil directly with a
> > > > HP
> > > > function generator ( Model 3310B). I placed a 1000 ohm resistor in
> > > > series
> > > > with the coil. I took my input signal from across the coil so I had
> > > > a
> > > > sensitivity of 1000 volts/amp. The output was taken at the output of
> > > > the
> > > > cap gauge circuit, after a 2 pole 35 Hz filter that would have been
> > > >
> > > > inconvenient to remove. The output device was a HP 54603B memory
> > > > scope. The
> > > > driven mass is pretty close to 500 grams.
> > > >
> > > > I attempted to take phase and P-P position data at constant
> > > > acceleration
> > > > from 0.1 Hz to 10 Hz while holding the current through the coil at
> > > > 94
> > > > microamps, i. e. 94 millivolts across 1000 ohms. Why that value?
> > > > Because it
> > > > was the maximum that I could use at 0.1 Hz and still maintain
> > > > linearity of
> > > > the cap gauge signal.
> > > >
> > > > Results:
> > > >
> > > > The force balance coil/magnet combination have a transfer function
> > > > of 0.26
> > > > Newtons/Amp.
> > > >
> > > > I lost the signal in the noise at about 6 Hz. Obviously, I could go
> > > > higher
> > > > with a larger input signal.
> > > >
> > > > The phase between acceleration and displacement was less than 20
> > > > degrees
> > > > throughout the range.
> > > >
> > > > The P-P displacement was about 60 nanometers at 6 Hz.
> > > >
> > > > The laws of physics still apply, as the P-P position signal was
> > > > inversely
> > > > proportional to the square of the frequency.
> > > >
> > > > There was no sign of roll-off due to damping from the cap gauge, but
> > > > then
> > > > the amplitudes were pretty low at the higher frequencies.
> > > >
> > > > Comment: My low pass filters are set to roll off at 5 Hz so data
> > > > beyond
> > > > that point is academic.
> > > >
> > > > Dave ...
> > > >
> > > > __________________________________________________________
> > > >
> > > > Public Seismic Network Mailing List (PSN-L)
> > > >
> > > > To leave this list email PSN-L-REQUEST@.............. with
> > > > the body of the message (first line only): unsubscribe
> > > > See http://www.seismicnet.com/maillist.html for more information.
> > > >
> > > >
> > >
> > >________________________________________________________________
> > >Sign Up for Juno Platinum Internet Access Today
> > >Only $9.95 per month!
> > >Visit www.juno.com
> > >__________________________________________________________
> > >
> > >Public Seismic Network Mailing List (PSN-L)
> > >
> > >To leave this list email PSN-L-REQUEST@.............. with
> > >the body of the message (first line only): unsubscribe
> > >See http://www.seismicnet.com/maillist.html for more information.
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: Tests on folded pendulum instrument
From: "David H. Youden" dyouden@.........
Date: Tue, 18 Mar 2003 17:22:09 -0500
Chris,
Thank you so much for the thoughtful critique. I really truly appreciate
your taking the time to look critically at this stuff. If nobody did
that, things would never get better. I just finished spending a small
fortune at Digi-Key. We'll see how much it helps.
Dave...
At 11:59 PM 3/17/03 -0500, you wrote:
In a
message dated 16/03/03, dyouden@......... writes:
I got a chance yesterday to run
some tests on my instrument.
Here's what I did:
Subject: Re: Slight revision of HeadpikV2
From: John or Jan Lahr johnjan@........
Date: Wed, 19 Mar 2003 08:11:53 -0700
Hi Bob,
I've updated the web site files: http://jjlahr.com/science/psn/mcclure/dataq2psn/
We're getting snowed under here in Colorado! I just hope the power
stays on.
Cheers,
John
At 05:34 AM 3/19/2003, you wrote:
Hi John,
Larry Cochrane noted a slight, invisible error in the conversion
of wdq to psn, caused by my misinterpretation of the PSN Type 4 format
description. I am therefore submitting the first of probably
several revisions of the program. It is now version 2.0.0.1.
There was a typo error in the readme file. The source code has also
been updated.
Regards,
Bob
Subject: Re: Tests on folded pendulum instrument
From: "David H. Youden" dyouden@.........
Date: Sun, 23 Mar 2003 07:36:50 -0500
Steve, and anyone else who has an interest,
I have a package of PSN4 files recorded with the folded pendulum, and will
send it to anyone who would like to see them.
Dave...
At 11:13 AM 3/17/03 -0800, you wrote:
>Hi David,, If your interested in converting your files to PSN format, you
>might
>try John Lahr's WDQ2PSN converter program,,, I use it with my Dataq DI-150RS
>and it works great!! You might ask John if it will work on your files???
>Hopefully, they are the same format????
>You can find it at:
>
>http://jjlahr.com/science/psn/gldn_psn.html
>
>Scroll down to the middle of the page to find his info and the link to the
>program!
>If yours are the same format and you decide to try it and have problems or
>questions, I'll be glad to try and help,,,, or if you would like to send
>a few
>minute of a recording, I'll try to convert it and let you know how or if it
>works!!! If your interested in seeing one of my traces converted to PSN
>format
>and then converted to a gif using the WINQUAKE program, you can see it on Bob
>Shannon's web site,, (it is the recording of the 4.0 Mammoth Lakes quake a few
>days back), when you get there click on TRACES,, at:
>
>http://www.televar.com/~earth/alert.html
>
> Stephen
> PSN Station #55
> near Pilot Hill Ca
> 38.828N 120.979W
>
>"David H. Youden" wrote:
> >
> > Jim,
> >
> > I use Dataq"s Windaq software for a variety of reasons, so my recordings
> > are not compatible with the more common formats. I do have a few, which I
> > would be happy to share with anyone who can handle the file format, or I
> > can make picture files of them in some common format e. g. GIF or JPG.
> >
> > Dave...
> >
> > At 09:59 AM 3/16/03 -0800, you wrote:
> > >Hi Dave- You got my attention- Nice work!- Do you have any records
> > >(seismograms) posted that we can look at?
> > >Jim O'Donnell - UNLV
> > >On Sun, 16 Mar 2003 11:57:47 -0500 "David H. Youden"
> > >writes:
> > > > All,
> > > >
> > > > I got a chance yesterday to run some tests on my instrument.
> > > >
> > > > Here's what I did:
> > > >
> > > > I opened the loop and drove the force balance coil directly with a
> > > > HP
> > > > function generator ( Model 3310B). I placed a 1000 ohm resistor in
> > > > series
> > > > with the coil. I took my input signal from across the coil so I had
> > > > a
> > > > sensitivity of 1000 volts/amp. The output was taken at the output of
> > > > the
> > > > cap gauge circuit, after a 2 pole 35 Hz filter that would have been
> > > >
> > > > inconvenient to remove. The output device was a HP 54603B memory
> > > > scope. The
> > > > driven mass is pretty close to 500 grams.
> > > >
> > > > I attempted to take phase and P-P position data at constant
> > > > acceleration
> > > > from 0.1 Hz to 10 Hz while holding the current through the coil at
> > > > 94
> > > > microamps, i. e. 94 millivolts across 1000 ohms. Why that value?
> > > > Because it
> > > > was the maximum that I could use at 0.1 Hz and still maintain
> > > > linearity of
> > > > the cap gauge signal.
> > > >
> > > > Results:
> > > >
> > > > The force balance coil/magnet combination have a transfer function
> > > > of 0.26
> > > > Newtons/Amp.
> > > >
> > > > I lost the signal in the noise at about 6 Hz. Obviously, I could go
> > > > higher
> > > > with a larger input signal.
> > > >
> > > > The phase between acceleration and displacement was less than 20
> > > > degrees
> > > > throughout the range.
> > > >
> > > > The P-P displacement was about 60 nanometers at 6 Hz.
> > > >
> > > > The laws of physics still apply, as the P-P position signal was
> > > > inversely
> > > > proportional to the square of the frequency.
> > > >
> > > > There was no sign of roll-off due to damping from the cap gauge, but
> > > > then
> > > > the amplitudes were pretty low at the higher frequencies.
> > > >
> > > > Comment: My low pass filters are set to roll off at 5 Hz so data
> > > > beyond
> > > > that point is academic.
> > > >
> > > > Dave ...
> > > >
> > > > __________________________________________________________
> > > >
> > > > Public Seismic Network Mailing List (PSN-L)
> > > >
> > > > To leave this list email PSN-L-REQUEST@.............. with
> > > > the body of the message (first line only): unsubscribe
> > > > See http://www.seismicnet.com/maillist.html for more information.
> > > >
> > > >
> > >
> > >________________________________________________________________
> > >Sign Up for Juno Platinum Internet Access Today
> > >Only $9.95 per month!
> > >Visit www.juno.com
> > >__________________________________________________________
> > >
> > >Public Seismic Network Mailing List (PSN-L)
> > >
> > >To leave this list email PSN-L-REQUEST@.............. with
> > >the body of the message (first line only): unsubscribe
> > >See http://www.seismicnet.com/maillist.html for more information.
> >
> > __________________________________________________________
> >
> > Public Seismic Network Mailing List (PSN-L)
> >
> > To leave this list email PSN-L-REQUEST@.............. with
> > the body of the message (first line only): unsubscribe
> > See http://www.seismicnet.com/maillist.html for more information.
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Web page
From: "Karl Koth" karl@............
Date: Mon, 24 Mar 2003 19:33:05 -0700
Hello,
I have just put my seismomter on the Web. Please give me feed back on =
anything you think needs to be added/changed.
http://karlkoth.tripod.com/
thx Karl
Hello,
I have just put my seismomter on the =
Web. Please=20
give me feed back on anything you think needs to be =
added/changed.
http://karlkoth.tripod.com/
thx Karl
Subject: Web Page Back up in 2 hours
From: "Karl Koth" karl@............
Date: Mon, 24 Mar 2003 21:27:43 -0700
Hello,
There were too many visitors at once and I got shut down for two hours =
because I was using too much bandwidth. It will be back up soon.
thx Karl
Hello,
There were too many visitors at once =
and I got shut=20
down for two hours because I was using too much bandwidth. It =
will be=20
back up soon.
thx Karl
Subject: RE: Web page
From: steve hammond shammon1@.............
Date: Mon, 24 Mar 2003 22:38:51 -0800
Looks good Karl, where is your system located?
Regards, Steve Hammond PSN San Jose, Aptos CA
-----Original Message-----
From: Karl Koth [SMTP:karl@.............
Sent: Monday, March 24, 2003 6:33 PM
To: PSN-L@..............
Subject: Web page
Hello,
I have just put my seismomter on the Web. Please give me feed back on anything you think needs to be added/changed.
http://karlkoth.tripod.com/
thx Karl
<< File: ATT00006.html >>
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: slow quake news item
From: "David Saum" dSaum@............
Date: Thu, 27 Mar 2003 12:35:12 -0500
full story
http://sfgate.com/cgi-bin/article.cgi?f=/news/archive/2003/03/26/state1636ES
T7193.DTL
Experts: Northwest quake under way _ taking weeks, not seconds
Wednesday, March 26, 2003
----------------------------------------------------------------------------
----
(03-26) 13:36 PST PORTLAND, Ore. (AP) --
A widespread earthquake is taking place beneath the Northwest, slowly
unleashing energy that may be equivalent to the magnitude 6.7 Nisqually
quake that rocked the region two years ago, experts say.
But the so-called "silent" or "slow" earthquake is releasing that energy
over weeks rather than in the sharp, seconds-long jolts of a typical quake.
No one can feel it.
........
Enjoy,
Dave
http://www.infiltec.com/seismo/
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: slow quake news item
From: George Bush ke6pxp@.......
Date: Thu, 27 Mar 2003 10:09:35 -0800
This is interesting-
For the last few days I have been seeing "packets" of low-freq waves coming
in. They last for a few minutes, fade away for 5 or 10 minutes, slowly
build up again, etc. They are in the freq range of about 6 to 10 sec per
cycle (I haven't checked the freq on Winquake yet). This is similar to the
normal swell action I see being just a block away from the ocean, but is
more regular and of a lower frequency.
I wonder if this is from the slow quake? Has anybody else detected this? I
would be glad to capture and upload a file to the PSN website if anyone is
interested.
At 12:35 PM 3/27/03 -0500, you wrote:
>full story
>http://sfgate.com/cgi-bin/article.cgi?f=/news/archive/2003/03/26/state1636ES
>T7193.DTL
>
>Experts: Northwest quake under way _ taking weeks, not seconds
>
> Wednesday, March 26, 2003
>----------------------------------------------------------------------------
>----
>(03-26) 13:36 PST PORTLAND, Ore. (AP) --
>
>A widespread earthquake is taking place beneath the Northwest, slowly
>unleashing energy that may be equivalent to the magnitude 6.7 Nisqually
>quake that rocked the region two years ago, experts say.
>
>But the so-called "silent" or "slow" earthquake is releasing that energy
>over weeks rather than in the sharp, seconds-long jolts of a typical quake.
>No one can feel it.
>.......
>
>Enjoy,
>
>Dave
>http://www.infiltec.com/seismo/
>
>
>
>
>
>__________________________________________________________
>
>Public Seismic Network Mailing List (PSN-L)
>
>To leave this list email PSN-L-REQUEST@.............. with
>the body of the message (first line only): unsubscribe
>See http://www.seismicnet.com/maillist.html for more information.
>
>
>
George Bush
Sea Ranch, CA, USA
38.74N, 123.5W
__________________________________________________________
Public Seismic Network Mailing List (PSN-L)
Subject: Re: WinDaq to WinQuake utility
From: John or Jan Lahr johnjan@........
Date: Fri, 28 Mar 2003 07:09:48 -0700
Hi Bob,
I am releasing to you the following zip file. It seems to
work fine. This package replaces earlier applications, such as
Headpik.exe and HeadpikV2.exe. If you offer the file for download,
please make it this entire zip file.
The above package allows Dataq A/D and WinDaq users the ability to
easily copy WDQ files to PSN Type 4 format.
HdrEditor.exe can either be run stand-alone or launched from
HeadpikX.exe. It is used to enter local coordinates, sensor
information, timing information in the same manner as provided in
WinQuake dialog boxes. This information is to be saved for repeated
use as a [Sensor Name].ps1 file when converting WDQ files to PSN
format.
HeadpikX.exe is a utility program for inspection of the header
contents or either WDQ or PSN files, and editing of WDQ file start time,
sampling period, and for entering sensor period and damping for use by
DrumPlot.exe or Shortplot.exe. It allows single channel files to be
assembled into multichannel files, or single channel files to be spliced
together. Conversion of WDQ files can be done either with or
without a header template file.
Additional features seldom used by those without programming or
digital filter experience allow the data contained in a PSN file to be
converted to a WDQ file to be filtered by "ShortPlot", saved,
and then plugged back in to a copy of the original PSN file, with
original PSN header information preserved intact.
The above exe and text files must reside in the same folder, any
folder. The "Headers" folder must be placed in the same
folder as the WDQ files.