I agree, Geoffrey-

The garage slab is a very poor seismic foundation. Not only do I get 
the car noise both for cars on the slab, but for cars in the street 
and driveway. Bedrock is about 12' down and what I hope to do is go 
out in the field away from the cars and drill 3 tilted holes to the 
bedrock and fill them with concrete to form a tripod that I will put 
a concrete top on to mount the seismometers on, and surround it with 
a little house for protection.

George

At 03:01 PM 1/9/2011, you wrote:
>I have often thought you might cut a slot through the concrete
>around the seismometer to isolate it from direct contact
>but should be done at the building of the foundation
>and not after.
>
>I would then dig a hole and drive some stakes
>like three set a level granite tile on the stakes
>even in your garage or basement such a cavity
>might make a good foundation for a seismometer.
>
>I once saw this IC manufacturing plant
>and noticed their major machines were
>vibration isolated with a slot like this
>in the foundation itself.
>It takes only a small vibration to destroy a whole batch
>of photo etchings or so I understand.
>
>
>-----Original Message----- From: George Bush Sent: Saturday, January 
>08, 2011 6:06 PM To: psnlist@.............. Subject: Re: Engine 
>Start/Shutdown Noise Spikes From Automobile



>...snip...


George Bush
Sea Ranch, CA, USA
38.73775N, 123.48882W 

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