Bell in a Jar Experiment Manufacturer,Supplier and Exporter in Africa
Product Code : DA-VAW-11280
Quick Answer: The Bell in a Jar Experiment shows that air is required to conduct sound: the bell is heard getting quieter as air is evacuated from the robust acrylic jar. The aluminium pump plate sits on a heavy tripod base, and a stopcock keeps the vacuum when the pump is turned off.
Last updated: October 2026
Key Features
- Robust acrylic bell jar with a flat flange for a good seal
- Lightweight aluminium pump plate on a heavy tripod base
- Rubber sheet seal, no vacuum grease needed
- Stopcock to seal the chamber and keep the vacuum
- Bell suspended by wires to reduce sound conduction to the jar
- Bell runs on 4-6 V DC or AC via 4 mm sockets on the top bung
Technical Specifications
| Specification | Value |
|---|---|
| Bell jar internal diameter | 140 mm |
| Flange external diameter | 180 mm |
| Bell jar height to neck | 260 mm |
| Pump plate diameter | 250 mm |
| Pump plate height | 195 mm |
| Bell supply | 4-6 V DC or AC |
About This Product
Air is drawn out of the jar through a tube connection to the central pillar of the pump plate, and the suspended bell is heard getting quieter. Closing the tap, turning off and disconnecting the pump, then slowly letting the air back in makes the bell louder again, because air is required to conduct the sound. The experiment requires a suitable vacuum pump and heavy-walled vacuum/pressure tubing.
Frequently Asked Questions
Q1. What does the Bell in a Jar Experiment need to run?
A suitable vacuum pump and heavy-walled vacuum/pressure tubing, plus a 4-6 V DC or AC supply for the bell, connected through 4 mm sockets on the top bung.
Q2. Is vacuum grease needed?
No. A rubber sheet on the base seals the jar to the pump plate, and the jar has a flat flange for a good seal.
Q3. Can the vacuum be held with the pump off?
Yes. A stopcock seals the chamber so the vacuum is kept when the pump is turned off.
Related: Vibrations and Waves range, Buzzer in a Vacuum Vessel, Air Pump Plate.
For a quotation on the Bell in a Jar Experiment, contact Didactic Africa.
