thescullster was thinking very hard :
Hi all

I have come by an old barometer - something like the item shown here
http://www.hemswell-antiques.com/ant...ter-33028.html
(although not quite of the quality).
Now I know that these devices measure atmospheric pressure, but I am not
clear on how much this will be affected by the instrument location.

Does a heat source like a radiator change atmospheric pressure?
Can I mount this on a wall above a radiator and expect it to work?

From my memory of the barometer, the needle doesn't appear to move much in
operation. Is this because it was previously in a centrally heated house, or
is there likely to be something wrong here?

Thanks

Phil

Pressure is the same pressure irrespective, providing it is in the same
geographical area. So mount it in any sensible location, but not over a
radiator as that will affect the wood. You can calibrate it, by
comparing it to your local weather station - note the pressure
indicated by your instrument, at the times the pressures are suggested
to be have measured, then compare your reading with what they suggest
the pressure was at that paticular time. From that, you should be able
to work out what your error was and make an adjustment.

Best to do it when the pressure has been steady for a good while
though, when the isobars are widely spaced / not much wind.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk