Re: Fortin Barometer Repair

["L. R. Cartwright (Larry)" <physics@SCNC.CPS.K12.MI.US>]

On Tue, 4 May 1999, Paul Yates wrote:
> Some kind soul took our Fortin barometer off the wall and placed it
> horizontal - all the mercury drained out of the tube.
> Does anyone have any information on how to fill these devices? Many hours
> have been spent in the past on trying to repair these, without much
> success. (Air bubbles like to stick to the inside walls.)

Tube must be clean and dry, mercury must be clean.  Keep the tube only a
few degrees from horizontal.  Introduce the Hg in small amounts (e.g. with
a dropper) and let it run slowly down the side of the tube (no splashing).
Then rotate tube to make sure there are no air bubbles.  Keep repeating
this sequence.  If done carefully and patiently, it works.  I have done it
3 times in 20 years; next one is somebody else's turn :-)

Best wishes,

Larry

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Larry Cartwright
Physics, Physical Science, Internet Teacher
Charlotte High School, 378 State Street, Charlotte MI 48813
<physics@scnc.cps.k12.mi.us> or <science@scnc.cps.k12.mi.us>

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"He is not necessarily the best teacher who performs the
most labour; makes his students work the hardest, and
bustle the most.  A hundred cents of copper, though they
make more clatter and fill more space, have only the tenth
of the value of one gold eagle."
- Emma Hart Willard, 19th century education pioneer
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