Bell in Jar with Air Pump STEM Lab
Product Code : SCL-ES-12507
Quick Answer: The Bell in Jar with Air Pump STEM Lab shows that sound needs a medium: a battery-operated electric bell rings inside a sealed transparent jar, and the sound fades as a manual hand vacuum pump draws the air out. The jar is about 250mm high and 150mm across.
Last updated: October 2026
Key Features
- Battery-operated electric ringer, 3V–6V DC
- Transparent jar, approx. 250mm high and 150mm in diameter
- Heavy non-slip ABS base with rubber sealing ring
- Manual hand vacuum pump with tubing connection
- Release valve to let air back in
- Complete kit weighs about 1.8 kg
Technical Specifications
| Specification | Value |
|---|---|
| Bell | Electric ringer, battery operated, 3V–6V DC |
| Jar size | Height approx. 250mm, diameter approx. 150mm |
| Base | ABS with rubber sealing ring |
| Pump | Manual hand vacuum pump |
| Kit weight | Approx. 1.8 kg |
About This Product
With the bell ringing under the jar, students pump the air out and hear the sound grow fainter until it almost stops, even though the striker can still be seen moving. Opening the release valve brings the sound straight back, which makes it clear that sound is a mechanical wave carried by air and cannot cross a vacuum. Laboratories and colleges in Egypt, Chile, Mongolia, Libya, Saudi Arabia and Tanzania can buy the Bell in Jar with Air Pump STEM Lab through an export order.
Frequently Asked Questions
Why does the bell go quiet in the Bell in Jar with Air Pump STEM Lab?
As the pump removes air from the jar there are fewer molecules to pass on the vibrations, so the sound cannot reach the listener even though the bell keeps ringing.
What does the bell run on?
It is a battery-operated electric ringer working on 3V–6V DC.
Related: Electrostatics & Sound and Tuning Fork with Resonance Box STEM Lab.
For a quotation on the Bell in Jar with Air Pump STEM Lab, contact Educational Instrument.
