Weird Weather Monitor 2 raingauge

Any owner of one these gauges may be intrigued by this story. It's well
known on this NG that the reed switch eventually dies - mine has lasted 10
years so a good run I think.
Anyway I checked out how to replace the reed switch and found a good little
site that gives clear instructions

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=32496&posts=6&start=1

This led me to the reed switch that I bought from maplins for £1.29 - I
bought 2 just in case.

I was helped by my friend who is a technician at Bradford University and he
had all the circuit testers etc.

AFter the first repair the gauge was under-reading against my 5 inch gauge,
so I decided to summon help again where it was discovered that
the reed switch was remaining in the closed position after tips and not
resetting itself.
The purpose of the magnet is to pull the connections inside the reed switch
apart after each tip so the circuit is broken again.

So back to my friends house. On the second trip we tested the reed switch
away from the gauge and positioned a very small six's max min magnet near
the contacts. This caused a current to flow as it should.
However, on positioning the reed switch in the gauge, and testing the
circuit during the tip, it was clear that the circuit remained open and did
not re-set itself as it should.
This explained why I was only recording an occasional tip and the gauge
under-reading.

So we spent an hour testing until we realised that if the small six's
thermometer magnet was positioned close to the reed switch within the
gaiuge itself it gave the expected result and each tip was recorded and the
circut was opening and closing as it should. I tested the gauge manually
and can't fault it now, but it begs the question why won't the reed switch
and the magnet operate normally without the six's thermometer magnet in
place within the gauge ?

The question that springs to mind - is this why the late models of weather
monitor 2 gauges under-read?

Rob
Farsley Near Leeds





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Relevant Pages

  • Re: Need help with intermittent circuit failures - JK Flip Flops
    ... Imagine the motor is turning in Direction "A", and the reed switch just ... contact with the magnet. ... Then I shut down the whole circuit intentionally ...
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  • Re: Need help with intermittent circuit failures - JK Flip Flops
    ... Imagine the motor is turning in Direction "A", and the reed switch just made ... contact with the magnet. ... Then I shut down the whole circuit intentionally ...
    (sci.electronics.basics)
  • Repair Success Dell XPS M140
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