Hi all,

The below is a reference to a web page with pictures I put up, where; a
older magnet and iron assembly
does essentially the same tasks as earlier outlined in many past PSN emails
by Chris Chapman.

http://seismometer.googlepages.com/magnetpu%26d

This old assembly could essentially be used obviously for either eddy
current dampening and copper
coil induction pickups in a seismometer.

A main point with using such in a home brew seismometer, is that with the
current availability of
strong field neodymium magnets in a wide span of sizes; its relatively easy
to fashion ones own
unit; rather than use a simple two pole (usually) alnico magnet, with a far
weaker magnetic field.

Meredith Lamb
Hi all,

The below is a reference to a web page with pictures I put up, where; a older magnet and iron assembly
does essentially the same tasks as earlier outlined in many past PSN emails by Chris Chapman.  



http://seismometer.googlepages.com/magnetpu%26d

This old assembly could essentially be used obviously for either eddy current dampening and copper

coil induction pickups in a seismometer.  

A main point with using such in a home brew seismometer, is that with the current availability of
strong field neodymium magnets in a wide span of sizes; its relatively easy to fashion ones own

unit; rather than use a simple two pole (usually) alnico magnet, with a far weaker magnetic field.

Meredith Lamb