Hi Brian
   I like your photos also . One of these days I hope to share also. I
currently use plexiglas for my lehman also. It has works well for me. I
was previously getting condensation in the winter due to moisture coming
thru my garage slab. I put a layer of plastic drop cloth under (the
thinist I could find (0.5 mil)). It solved that  problem. I also put a
strip of weather stripping(sticky on one side) under the where the
plastic contacts the concrete to help with slab irregularities.Looks
like you have a slightly different arrangement which probably works as
well. I am still concerned about the lack of emi shielding of my use of
a  plastic cover, but possibly the low pass filters take care of most of
this ,since we look at very low(relatively speaking)frequencies. I have
blown a few opamps due to lightning. I haven't incorporated circuit
overloads for this problem yet.
Regards
Barry

Bryan & Regina Goss wrote:

> Well I finally got my sight updated tell me what you all think.Just
> wandering if anyone else had used a Plexiglas box for a
> cover...... http://www.freedom2000net.com/userpages/bgoss/seis/index.htm



Hi Brian

   I like your photos also . One of these days I hope to
share also. I currently use plexiglas for my lehman also. It has works
well for me. I was previously getting condensation in the winter due to
moisture coming thru my garage slab. I put a layer of plastic drop cloth
under (the thinist I could find (0.5 mil)). It solved that  problem.
I also put a strip of weather stripping(sticky on one side) under the where
the plastic contacts the concrete to help with slab irregularities.Looks
like you have a slightly different arrangement which probably works as
well. I am still concerned about the lack of emi shielding of my use of
a  plastic cover, but possibly the low pass filters take care of most
of this ,since we look at very low(relatively speaking)frequencies. I have
blown a few opamps due to lightning. I haven't incorporated circuit overloads
for this problem yet.

Regards

Barry
Bryan & Regina Goss wrote:

Well
I finally got my sight updated tell me what you all think.Just
wandering if anyone else had used a Plexiglas box for a cover...... http://www.freedom2000net.com/userpages/bgoss/seis/index.htm