PSN-L Email List Message

Subject: Geophone Questions
From: Dave Willey davewilley@.............
Date: Thu, 9 Nov 2006 01:28:37 -0800 (PST)


Iíve got one of Larryís geophone systems for detection just local activity. 
Maybe Iíll build a SG sensor later on.

But for now, Iím now moving my geophone away from the house to out back in an area that is relatively isolated...

I am trying to come up with a container of some sort to house one of Larryís 3 axis geophone, and some way to develop the  new site for the geophone.

Several questions come to mind:

Iíve seen talk on controlling the temp in SG type sensors.  But nothing specific to 4.5 Hz geophones.  Iíve also heard talk on the list of folks burying the geophones in the ground.  So it would seem to me that I would not need to temp stabilize the geophone  if they are down 4 Ė 6 feet in the ground  So temperature stabilization of a geophone would be major overkill?

Just for background.  I have 180 feet between the top of the ground and bedrock (bummer!), so I canít place the geophone on bedrock.  As much as I like to.

8Ē dia thick walled PVC water pipe and end caps are relatively easy to obtain locally.  Any reason not to bury 4 Ė 6 feet of vertical pipe in the ground and place the geophone glued in the bottom of the cap? 

The geophone case itself is cracked and no longer waterproof.  So I am planning to make the PVC pipe waterproof   Will barometric pressure changes affect the geophone? Should I allow air pressure to equalize by placing a small breath hole in the PVC at the top where the wires are located??

Or does anyone have a better idea / suggestion as a way to develop a new site for a geophone?  (Other than moving to a site with exposed bedrock.)


Thanks,


Dave Willey


Iíve got one of Larryís geophone systems for detection just local activity.
Maybe Iíll build a SG sensor later on.

But for now, Iím now moving my geophone away from the house to out back in an area that is relatively isolated...

I am trying to come up with a container of some sort to house one of Larryís 3 axis geophone, and some way to develop the  new site for the geophone.

Several questions come to mind:

Iíve seen talk on controlling the temp in SG type sensors.  But nothing specific to 4.5 Hz geophones.  Iíve also heard talk on the list of folks burying the geophones in the ground.  So it would seem to me that I would not need to temp stabilize the geophone  if they are down 4 Ė 6 feet in the ground  So temperature stabilization of a geophone would be major overkill?

Just for background.  I have 180 feet between the top of the ground and

[ Top ] [ Back ] [ Home Page ]