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Subject: not to dismantle the KS36000
From: sean@...........
Date: Mon, 30 Apr 2001 16:11:51 -0500 (CDT)

A further note regarding dismantling the KS36000.

Since it is a triaxial sensor, individual parts of it would
be essentially useless curiosities. It is designed to work IN
the borehole casing with the three U,V,W. sensors summed to make
the orthogonal outputs, as I and Dennis described. I think it would 
be ill advised to "break it down", which would be to brake it period.
A single 53 deg. sensor is not a useful seismometer. Since these were
working systems when they were replaced by the KS54000s (some KS36ks
are reported to still be in service), I think that a high priority 
should go to anyone who wants to spend the effort to install and 
operate one. I think that the analog electronics should be relatively
easy to work with (no mysterious embedded micros), especially if
the manuals can be found. (Has anyone asked Dr. Hutt about these?).

The marvel of these systems is not so much in the electronics but
in the mechanical engineering to minimize noise while still allowing
the flexibility needed for remote centering and leveling while being
rugged enough to be dragged to the ends of the earth ( i.e. around the 
former USSR) and surviving some moderate bumps. Everything that I have
ever used from Geotech has been designed to last forever, so I don't
think that deterioration from age is a factor. (The main reason that the
KS36000 was replaced by the KS54000 is that the latter is a broadband
fedback instrument using '90s technology.) I would love to have a single 
KS36k sensor module just to admire the construction.

Although the KS36K is designed for deep boreholes to avoid wind and
barometric deformation noise to allow maximum sensitivity, a shallow hole
should be adequate for the thermal stability (temperature changes are
attenuated by approximately the cube root of the depth) needed for 
general teleseism detection.  I think that the comment by R. Hutt that
some components are "noisy" means that they still work but have noise
levels above the original specifications. One would want to install
one and operate it to see just what the noise level is.

If one wants to install and operate one, I think that a 10 ft borehole
can made with a bucket auger, with a tripod, rope and pulley to lift it,
(I have been able to go well over 10 meters by adding sections to the 
auger pipe; not exactly straight, and sometimes hit water).

You can case the hole with a 10' length of schedule 80 ABS pipe. The 
tripod, made with three 21ft lengths of chain fence corner post tubing 
(1 1/2"dia) is also useful for lowering the intact instrument into the 
hole. The limited availability of the installation test sets will 
require some cooperation, and it may even be possible to pool resources
and do a collaborative effort in one area, like Denver.


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