Hi folks,

Does anyone here have experience of getting the air out of a mercury barometer column? My barometer looks like this:

http://www.messcom.de/MESSCOM/MDO/pd...0Bedienanl.pdf

I had wondered about putting the whole barometer in a vacuum chamber, but I'm not sure if this will work. Unfortunately there's nowhere to connect a vacuum pump at the top of the column.

Is there anyone with experience here who can give me some tips? So far, I've been trying to avoid taking the barometer apart in case I lose the precious (and slightly dangerous) mercury.

The amount of air inside is enough to change the reading by 10 to 20 mm.

Best wishes,

Chris