PSN-L Email List Message

Subject: Re: Questions from a beginner
From: "Larry Conklin" lconklin@............
Date: Wed, 2 Aug 2000 12:09:19 -0400

Jack Ivey wrote

> I have noticed that when my Lehman has its pivot against
> the basement wall (with the pendulum sticking out into the
> basement), this seems to minimize the noise from activity
> in the house.  When I tried it in the middle of the floor,
> could see (it seemed) a squirrel jumping on the roof.  I
> finally realized that this was because I had placed the left
> foot of the Lehman directly next to a support column, which
> was translating load changes on the first and second floor
> into tilt noise.

> When seismo is placed in the middle of the wall with the
> sensitive axis along the wall, the wall will move up and down
> with load changes,but there is relatively little translation into
> tilt sue to symmetry.

I also have assumed that a spot in the middle of the floor would be
better, because it would be separated from structural loads communicated
through the walls.  Due to interior walls in the basement, and support
columns, I can't get far enough away from everything to test the theory.
Your symmetry effect isn't too noticeable in my case.  My most important
move was away from the driveway.  Up till that point I had a Toyota


By the way, does a "reply to sender" post go back to the list or to the
sender only?  I'm on another list that sends this kind of response back to
individual, rather than the entire list.


Public Seismic Network Mailing List (PSN-L)

[ Top ] [ Back ] [ Home Page ]

Larry Cochrane <cochrane@..............>