PSN-L Email List Message

Subject: Re: Seismic recorders and geophones available - free to a good home
From: Larry Cochrane lcochrane@..............
Date: Mon, 21 Mar 2005 14:26:34 -0800

Hi Everyone,

I received this email the other day. The geophones are not very useful for earthquake 
recording since they are 8 hz units. Since Stanford is near by I could pick up and 
ship some units to people who are interested in having one of the records and/or 
sensors. I have no idea how big the records are so I have no idea what the shipping 
costs would be.

Larry Cochrane
Redwood City, PSN

Simon Klemperer wrote:
> Gray Jensen (USGS) suggested that you might have an interest, or know 
> of someone who might have an interest, in  industry geophones.
> Simon Klemperer
> Subject: Seismic recorders and geophones available - free to a good home
> Stanford University is disposing of about 180 Seismic Group Recorders 
> (SGR-III) and associated geophone strings.
> The SGR III is a single-channel, digital seismic recorder with a 
> theoretical dynamic range of 156 dB. Data are sampled at 500 samples 
> per second (or at 2 ms intervals) by a 12 bit A/D converter with gain 
> ranging from 0-90 dB in 6 dB steps, recorded on cartridge tape. 
> Total available recording time is about 30 minutes, with up to about 
> 100 programmable windows.  The SGR's have been modified by the USGS 
> to turn on at preset times instead of using the  standard radio turn 
> on. Timing is provided by a TXCO with an accuracy of 0.1 ppm (most 
> SGR clocks drift less than 20 milliseconds during a 24-hour period). 
> The SGR III recorders were designed by Amoco Production Company, 
> built by Globe Universal Sciences, Inc., and modified by the USGS. 
> IRIS-PASSCAL helped maintain the SGR system as a recording facility 
> available to PASSCAL users through the 1990s, and they were used very 
> successfully alongside the Refteks in many major controlled source 
> experiments.
> Not all our recorders work - the facility was last used in 2001, and 
> the SGRs have been in storage ever since. We have available a 
> miscellaneous supply of spare boards, manuals, connectors, etc.
> I estimate the cost to get each unit back in the field for a single 
> experiment would be >$50, and in a recent experiment in the western 
> USA I found it more cost-effective to pay for air-freight shipping of 
> Texan recorders from Europe, than to bring the SGR system out of its 
> current retirement. 
> For each SGR III we also own a single string of 6 modified Mark 
> Products L-10B vertical-component geophones (8 Hz) connected in 
> series, with c. 1 m cable between each phone.
> We also own a large number of strings of 12 L-10B vertical phones, 
> and of 12 horizontal phones, in each case with c. 15 m cable between 
> each phone, one string per clip.
> I would consider offers to take all or any part of our equipment. 
> You would need to pay shipping.
> Even if you are not interested, but know of anyone who would want 
> e.g. single geophones for teaching purposes, please forward this 
> message.


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