Another thought:

I'm not familiar with the Ward's seismometer, but can you separate the
electronics from the mechanical part of things?  If it is possible to
operate the amplifier and other electronics with the source being a
resistor rather than the instrument itself, that could isolate it to a
power supply or RFI getting into the electronics.

Also, if the exact time of the change seems to be a function of clouds in
the sky, that would point toward something associated with a light sensor
somewhere.

If the unit was operating when the time changed (assuming it did in your
area) from standard to daylight savings time, did the timing of the effect
follow the change in clocks?

Keep us posted about what you find.

Regards,
Karl Cunningham


At 09:36 PM 7/24/2000 -0500, you wrote:
>Hi,
>My name is John Tacinelli and I am new to the list.  I have one of the
Ward's seismographs.  It is working pretty well ( I picked up the Kodiak
Island quake on the 10th.)  My problem is that at 8:45 PM every night I get
a sudden increase (or decrease) in voltage through my amplifier that causes
the trace to move off to the right hand side of the screen.  It stays there
until 5:45 every morning.  Then it goes right back.  The seismograph itself
doesnt seem to move.  I have run it on an uninterruptible power supply and
it still does it.  I watched it happen tonight and I could detect no
environmental change in the area of the seismograph.  
>The seismograph is set up at the school where I teach.  Maintenance
thought it might be the outside lights turning on but that happens much
earlier.  That timing happens to coincide with the setting and rising of
the sun (pretty close) but I can't think of anything solar that could
affect a magnetic coil inside a building in a time span of about 2 seconds.
I should mention that I have contacted Wards and they are stumped.  Also
the timing seems to be getting earlier, both in the evening and morning by
about 30-40 seconds every day.  If anyone can help me out I would really
appreciate it since this problem is very vexing.  Thanks alot.  I hope to
be a regular contributor and I look forward to hearing from you all.
>
>John Tacinelli
>Earth Science Instructor
>Rochester Community and Technical College
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