Bell Jar and Ringer

Excellent bell jar apparatus.

The bell jar works as advertised and is a great way to demonstrate the fact that sound has to have a medium to travel through. I was able to pull the pressure down to about 30 microns ( 0. 03 Torr) after sealing the gasket with high vacuum grease. One suggestion is to hang the ringer from the apex of the jar so that sound of the ringer disappears completely when it is under vacuum.

Hose not compatible with companion pump. No vacuum grease for seal. Worked well but no vacuum release valve