I came across the following reference to testing the damping of 
geophones etc. and wondered if anyone had tried it?
       http://www.ednmag.com/reg/1996/030196/05di2.htm
       I also wondered if this couldn't be adapted to testing the damping of 
seismometers? Could you set up the damping with a relatively short period and 
only then lengthen the period?

       There are references to 4 Geophone Mfgrs at 
http://www.tenrats.org/geo.shtml
and a range of other info.

       Regards,

       Chris Chapman 
       I came across the following reference to testing
 the damping of 

geophones etc. and wondered if anyone had tried it?

       http://www.ednmag.com/reg/1996/030196/05di2.htm

       I also wondered if this couldn't be adapted to testing the damping of 

seismometers? Could you set up the damping with a relatively short period and 

only then lengthen the period?



       There are references to 4 Geophone Mfgrs at 

http://www.tenrats.org/geo.shtml

and a range of other info.



       Regards,



       Chris Chapman