PSN-L Email List Message

Subject: Geophone questions
From: "tchannel" tchannel@..............
Date: Sun, 27 May 2007 06:43:11 -0600


I have a few questions about magnets and coils:

1  I have seen a cross section of a Geophone, magnet, spring and mass =
etc.  When used in a Seismic Sensor, how is it dampened, or is it do =
electronically?

2 I am making a new vertical sensor, and this question has to do with =
the coil and magnet.  The coil is a spool with a 1" dia. hole in the =
center.  The thickness of the coil is 3/4"   The value of the coil is =
500ohms.   The magnet will be suspended from a rod and centered in this =
1" hole. Left to Right and Top to Bottom.

I can choose from three magnets.  One magnet 1/4" thick x 3/4" dia. =
centered leaving 1/4" of coil above and below the magnet......... OR Two =
magnets 1/4" thick, together to equal 1/2" x 3/4", leaving 1/8" of coil =
above and below the two magnets when centered........... Lastly I could =
use One magnet 1/2" thick x 3/4" dia. leaving 1/8" above and below.

This is a basic question about the magnet's surface and the N/S poles,  =
I do not know the science, but just curious about just these three =
scenarios, which arrangement is the best?.....I could try all three and =
measure the result, but in theory is it better one way or the other?








I have a few questions about magnets = and=20 coils:
 
1  I have seen a cross section of = a Geophone,=20 magnet, spring and mass etc.  When used in a Seismic Sensor, how is = it=20 dampened, or is it do electronically?
 
2 I am making a new vertical sensor, = and this=20 question has to do with the coil and magnet.  The coil is a spool = with a 1"=20 dia. hole in the center.  The thickness of the coil is = 3/4"   The=20 value of the coil is 500ohms.   The magnet will be suspended = from a=20 rod and centered in this 1" hole. Left to Right and Top to = Bottom.
 
I can choose from three = magnets.  One magnet 1/4" thick x 3/4" dia. centered = leaving 1/4"=20 of coil above and below the magnet......... OR Two magnets 1/4" = thick,=20 together to equal 1/2" x 3/4", leaving 1/8" of coil above and below the = two=20 magnets when centered........... Lastly I could use One magnet 1/2" = thick x 3/4"=20 dia. leaving 1/8" above and below.
 
This is a basic question about the = magnet's surface=20 and the N/S poles,  I do not know the science, but just curious = about just=20 these three scenarios, which arrangement is the best?.....I could try = all three=20 and measure the result, but in theory is it better one way or the=20 other?
 
Thanks, Ted

[ Top ] [ Back ] [ Home Page ]