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Kerry Shores and I have already discussed setting up the Campbell
Scientific datalogger to monitor the temperatures. We are planning on
setting it up next week once we know where the monitor points need to
be.<br>
<br>
Doug<br>
<br>
Jim Jackson wrote:
<blockquote cite="mid:200810161932.m9GJWd7w013820@revere.aoc.nrao.edu"
type="cite">
<pre wrap="">We have a Campbell Scientific data logger we have used in the
antennas for similar measurements. I believe Doug Gerrard has it and
probably knows the most about setting it up.
There are also some small USB temperature loggers around. These run
on batteries, look like a small thumb drive and you plug them into a
USB port to dump the data. I don't know who has them - they were
being used in a few antennas to monitor the HVAC.
Do any of the nearby Cisco network switches have temperature
monitoring? I think some of the Cisco boxes around here do. If so,
you might check them to see if they show the same thing. James
Robnett or Fred Dunn would be the best to ask about that.
Jim Jackson
At 10:27 AM 10/16/2008, Kevin Ryan wrote:
</pre>
<blockquote type="cite">
<pre wrap="">The WIDAR Prototype Correlator (PTC) is in a half-height rack sitting
in a corner in the outer screen room in the old VLA correlator room.
It contains 5 boards each with 5 or 6 temperature sensors. While
developing software to monitor these temperatures, I've noticed a
weird oscillation that occurs for a ~ 2-hour period roughly centered
around midnight local time. I've asked Ray Ferraro and Bob Broilo
about it but they did not know of anything that would cause it other
than that Ray stated that the temperature in that corner is affected
by the doors opening and closing.
So now I'm asking more people for ideas. A graph of the temps on one
board (they are all similar) over the last two days can be seen here:
<a class="moz-txt-link-freetext" href="http://www.aoc.nrao.edu/asg/widar/temps/mystery-ptc-temps.jpg">http://www.aoc.nrao.edu/asg/widar/temps/mystery-ptc-temps.jpg</a>
The swings from normal daily activity are apparent starting around
0600 - presumably from the door opening and closing and use of the
boards for testing - but what about those oscillations around midnight?
It is certainly possible that this is not being caused by ambient
temperature swings at all; like something going on on the boards
themselves or possibly even the data gathering system itself. Can we
place a recorder near the PTC to monitor its ambient temperature for
24-hours?
Kevin
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