Hi all,

Here is a "review" of a 3 magnet arrangement; that might be applicable and
useful
for that specific round copper wire coil you are having difficulty finding
the proper
metal and/or magnets for your seismometer sensor experimentation.  It will
via
the 3 neodymium magnets; be a improvement over using a weak field single "U"
shaped alnico magnet.

http://www.geocities.com/meredithlamb/neodymium.html

Take care, Meredith Lamb
Hi all,
 
Here is a "review" of a 3 magnet arrangement; that might be applicable and useful
for that specific round copper wire coil you are having difficulty finding the proper 
metal and/or magnets for your seismometer sensor experimentation.  It will via
the 3 neodymium magnets; be a improvement over using a weak field single "U"
shaped alnico magnet.  
 
http://www.geocities.com/meredithlamb/neodymium.html
 
Take care, Meredith Lamb