Doug,

You wrote, "Assuming that the ADXL devices are not useful, does 
anyone have any other recommendations for accelerometers
that would yield a better S/N ratio?"

Here's a message that I put on the PSN back in April.  John Evans is
using these sensors for seismic recording - although I'm not sure
which model is currently preferred.

JCLahr

>Because of the possible interest to PSN members,
>I've put a copy of John Evans' USGS Open-file Report on
>The Design and Performance of a Low-cost Strong-motion
>Sensor onto the following web page:
>
>http://geohazards.cr.usgs.gov/evans/ofr_98_109.html
>
>This address will work for the next few weeks, but
>eventually John E. will be moving the report to a USGS web
>server in Menlo Park.  The bulk of the report is in PDF format;
>free readers are available here:
>
>http://www.adobe.com/prodindex/acrobat/readstep.html
>
>in case you don't have one already.


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