>> Hi all,
>>
>> Dennis recla wrote me this email on the ks36000, he used to
>> work on them years ago.  Basically it uses capacitive sensor/s
>> and NOT the LVDT type as I mentioned earlier today as a
>> (false) assumption/guess.  Their is plus's and negatives.
>
      Here is his forwarded email...and, thanks Dennis for the email and
excellent
description!

>>
>>
>>
>> Dennis Recla wrote:
>>
>> > Hi MeredithSince I can't leave e-mail on PSN, I'll send this one to
>> > you.The KS-36000 (KS for Kirkpatrick / Starkey the engineers that
>> > designed it) seismometer, consists of 3 malt/shake can sized
>> > sensors that hang one above the other and make use of a capacitive
>> > type sensor to monitor 120 degrees of orientation.  I don't recall
>> > if the unit itself provides NS EW & V or if it gives just the
>> > output from each canister and the user has to convert them to the
>> > correct directions.  The test box provides the necessary voltages
>> > and controls to level the canisters, they use a blast of air from a
>> > small cylinder inside the case, to float the canister to level each
>> > unit.  They are suspended on a ball support thingee, the air
>> > provides a bearing and it levels and when the air is removed it is
>> > level.  The test box lets you know if each canister is level, and
>> > if you need to run the motor / air cylinder again to level
>> > them. Each unit has a hole lock, and an orientation base, that gets
>> > locked into the borehole.  The test box is also used to control the
>> > hole lock.  Seems like it was a 6 inch diameter borehole, but
>> > perhaps 8 inch.  (Sorry it's been years since I worked with one of
>> > them).  It's a pain to get them open, since it was designed for a
>> > deep hole, and they are well sealed. Each canister is in a vacuum
>> > that is then back filled with helium (I think that's what was
>> > used).  The fill gas had to be a small molecule since the air
>> > molecules hitting the mass would cause noise in the sensor.  It
>> > provides LP and SP outputs from the sensor.  Generally if they get
>> > noisey, the seal has been lost from the canister.  At the factory,
>> > each canister was put in a temperature chamber, heated, and
>> > evacuated using a multi-stage vacuum system then backfilled.There
>> > isn't an coil and magnet assemblies in the seismometer, it's a
>> > capacitive array, a little like the tuning capacitor of an old
>> > radio set.  Each sealed canister detects 120 degrees of direction,
>> > and when combined provide a 360 degree output.  If you can't use
>> > them as they are, there isn't much in the way of parts to build
>> > another seismometer from. That's about all I can contribute on
>> > these units right now, there are still several stations running
>> > these units, but it's been replaced by the KS-54000
>> > seismometer.Dennis
>>




Hi all,
Dennis recla wrote me this email on the ks36000, he used to

work on them years ago.  Basically it uses capacitive sensor/s

and NOT the LVDT type as I mentioned earlier today as a

(false) assumption/guess.  Their is plus's and negatives.

      Here is his forwarded email...and, thanks
Dennis for the email and excellent

description!

 

 
Dennis Recla wrote:
Hi
MeredithSince
I can't leave e-mail on PSN, I'll send this one to you.The
KS-36000 (KS for Kirkpatrick / Starkey the engineers that designed it)
seismometer, consists of 3 malt/shake can sized sensors that hang one above
the other and make use of a capacitive type sensor to monitor 120 degrees
of orientation.  I don't recall if the unit itself provides NS EW
& V or if it gives just the output from each canister and the user
has to convert them to the correct directions.  The test box provides
the necessary voltages and controls to level the canisters, they use a
blast of air from a small cylinder inside the case, to float the canister
to level each unit.  They are suspended on a ball support thingee,
the air provides a bearing and it levels and when the air is removed it
is level.  The test box lets you know if each canister is level, and
if you need to run the motor / air cylinder again to level them. Each
unit has a hole lock, and an orientation base, that gets locked into the
borehole.  The test box is also used to control the hole lock. 
Seems like it was a 6 inch diameter borehole, but perhaps 8 inch. 
(Sorry it's been years since I worked with one of them).  It's a pain
to get them open, since it was designed for a deep hole, and they are well
sealed. Each
canister is in a vacuum that is then back filled with helium (I think that's
what was used).  The fill gas had to be a small molecule since the
air molecules hitting the mass would cause noise in the sensor.  It
provides LP and SP outputs from the sensor.  Generally if they get
noisey, the seal has been lost from the canister.  At the factory,
each canister was put in a temperature chamber, heated, and evacuated using
a multi-stage vacuum system then backfilled.There
isn't an coil and magnet assemblies in the seismometer, it's a capacitive
array, a little like the tuning capacitor of an old radio set.  Each
sealed canister detects 120 degrees of direction, and when combined provide
a 360 degree output.  If you can't use them as they are, there isn't
much in the way of parts to build another seismometer from. That's
about all I can contribute on these units right now, there are still several
stations running these units, but it's been replaced by the KS-54000 seismometer.Dennis