Piezo Buzzer in Vacuum Chamber

A Better Bell Jar and Ringer!Our Piezo Buzzer in Vacuum Chamber is the modern replacement for the Bell Jar & Ringer. The apparatus features a piezo buzzer enclosed within a clear acrylic tube suspended between two posts limiting the transfer of sound, and is controlled by a switch that has a red LED attached to show that it is on. When the unit is connected to a vacuum pump, the air can be removed, and the effect of sound being unable to pass through a vacuum clearly demonstrated. Sound returns when the air is allowed back into the chamber. An effective demonstration with none of the complications of the traditional apparatus. GENERAL NOTES A motorized pump should evacuate the chamber in about 30 seconds to 1 minute.  Removal of air is rapid initially, but as the density of the air reduces, the amount removed is less.  Running the pump for 2 minutes does not remove twice as much air as for 1 minute. The sound level from the generator is very high in open air.  When it is placed in