PSN-L Email List Message
Subject: Re: TELEDYNE GEOTECH HELICORDERS
From: "James Allen" jcallen1@...........
Date: Wed, 22 Apr 2009 19:54:20 -0700
There is a large lot of Teledyne Geotech Helicorders just listed on Ebay =
today. Problem is, it is a very large "lot auction" that would entail =
shipping cost for hundreds of pounds of equipment.
James Allen
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Sent: Thursday, October 02, 2008 4:33 PM
Subject: Re: Torsion Seismometer
In a message dated 2008/10/02, tchannel1@............ writes:
I have seen something similar somewhere on the web, but I can't find =
it. This is all I could find. If someone has tried this please email =
me. Thanks, Ted
Torsion Seismometer Wood Anderson
http://www.data.scec.org/Module/s3inset3.html
Hi Ted,
The Wood-Anderson was a horizontal system with a torsion =
suspension, magnetic damping, optical + photographic recording and a =
period of about a second. There is no reason why you could not fit a =
dual Si photocell readout system.=20
To increase the period you can reduce the wire diameter / =
increase the wire length / mount the mass on an extended side boom to =
increase the inertia.
Check out
http://doga.ogs.trieste.it/doga/risk/woodanderson/index.html
http://www.eas.slu.edu/Earthquake_Center/Instruments/
Randall Peters has a vertical torsion device on this website.
http://physics.mercer.edu/hpage/peters.html
Regards,
There is a large lot of Teledyne =
Geotech=20
Helicorders just listed on Ebay today. Problem is, it is a very =
large "lot=20
auction" that would entail shipping cost for hundreds of pounds of =
equipment.
James Allen
----- Original Message -----
Sent: Thursday, October 02, =
2008 4:33=20
PM
Subject: Re: Torsion =
Seismometer
In a=20
message dated 2008/10/02, tchannel1@............=20
writes:
I have seen something similar somewhere on the web, but =
I can't=20
find it. This is all I could find. If =
someone has=20
tried this please email me. Thanks, Ted
Torsion =
Seismometer Wood=20
Anderson
http://www.data.sc=
ec.org/Module/s3inset3.html
Hi=20
Ted,
The Wood-Anderson was =
a=20
horizontal system with a torsion suspension, magnetic damping, optical =
+=20
photographic recording and a period of about a second. There is no =
reason why=20
you could not fit a dual Si photocell readout system.=20
To increase the period =
you can=20
reduce the wire diameter / increase the wire length / mount the mass =
on an=20
extended side boom to increase the=20
inertia.
Check=20
out
=20
=
http://doga.ogs.trieste.it/doga/risk/woodanderson/index.html
&nb=
sp; =20
=
http://www.eas.slu.edu/Earthquake_Center/Instruments/
=
=20
Randall Peters has a vertical torsion device on this=20
website.
=20
=
http://physics.mercer.edu/hpage/peters.html
&nbs=
p; =20
Regards,
Chris =
Chapman=20
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