Bell in a Jar Experiment

An improved version of the classic Bell in Jar experiment. The base is fitted with rubber sheet which ensures a good seal between the jar and pump plate, without the need for vacuum grease. The pump plate is lightweight aluminium, mounted on a heavy tripod base, with a tube connection to the central pillar to evacuate air from the bell jar on top. A stopcock allows the chamber to be sealed, allowing the vacuum to be kept when turning off the pump.
The bell jar is robust acrylic which is safe in the event of implosion, and has flat flange to ensure good seal with the pump plate. The bell is suspended by wires to reduce conduction of sound to the bell jar. Connection is by 4 mm sockets on the top bung.
The bell can be heard getting quieter as the air is evacuated. Then, by closing the tap, turning off and disconnecting the pump, and then slowly allowing the air back in, the bell can be heard getting louder, as air is required to conduct the sound.
The high-quality bell operates on 4-6 V DC or AC. Requires suitable vacuum pump, and heavy-walled vacuum/pressure tubing, diameter 8 - 9 mm.
Dimensions:
Bell Jar
• Height 260 mm to neck
• Internal diameter 140 mm
• External diameter flange 180 mm
Pump Plate
• Height 195 mm
• Diameter 250 mm