Bell Jars
Product Code : LSK-PL-10321
Bell Jars (SKU LSK-PL-10321) is a vacuum demonstration unit made up of a sturdy baseplate with a tap, a glass bell jar and a detachable battery-operated bell. Connected to a vacuum pump, it shows properties of a vacuum, for example that sound cannot pass through it. It serves school physics demonstrations and college labs. Science Lab Supplies manufactures the unit at its Saha, Ambala works (Plot 448, HSIIDC Industrial Area, India) and quotes schools, colleges, tender contractors and distributors directly.
Specifications
The glass bell jar stands on a sturdy baseplate fitted with a tap, through which air is pumped out or let back in. Inside, a detachable battery-operated bell rings while the air is removed. The unit works with a hand vacuum pump, though an electric vacuum pump is the better choice.
| Parameter | Value |
|---|---|
| SKU | LSK-PL-10321 |
| Vessel | Glass bell jar |
| Base | Sturdy baseplate with tap |
| Sound source | Detachable battery-operated bell |
| Pump | Hand pump or, preferably, electric vacuum pump (not included) |
| Manufacturer | Science Lab Supplies, Saha, Ambala, Haryana |
| Country of origin | India |
Applications and Experiments for the Bell Jars
The classic use is the bell-in-a-vacuum experiment: as air is pumped out, the ringing bell grows fainter, showing that sound needs a medium. Because the bell detaches, the jar and baseplate can also hold other objects for vacuum and air-pressure demonstrations.
- NCERT Class 8 and Class 9 science (Sound): sound needs a medium to travel.
- Air-pressure demonstrations with the bell removed, such as a balloon expanding under reduced pressure.
- College physics: introducing vacuum techniques and pumps.
Safety: glass under vacuum can implode, so handle the jar with care and let air back in slowly through the tap after each run.
Standard Scope of Supply
Each unit comprises the sturdy baseplate with tap, the glass bell jar and the detachable battery-operated bell. The vacuum pump is not included: a hand vacuum pump or an electric vacuum pump from the physics range can be added to the same quotation.
Packing, MOQ and Lead Time
Quotations can cover one demonstration unit or several for different labs. Each gives the packing, delivery time and price for the quantity, and because glassware is involved the packing method is stated on the quotation; a pump can be listed alongside.
Science Lab Supplies is a registered exporter with an Importer-Exporter Code, so it can ship to buyers in Ethiopia, Tanzania, Uganda, the UAE, Saudi Arabia and Oman. Send the requirement through the contact page, use the enquiry cart, or check the lab tender page for tender enquiries.
Frequently Asked Questions
Is a vacuum pump included with the bell jar?
No. The unit is the baseplate with tap, bell jar and bell. It can be used with a hand pump, but an electric vacuum pump is recommended; either can be quoted with it.
What does the bell jar experiment demonstrate?
It demonstrates the properties of a vacuum. With the bell ringing inside, pumping out the air makes the sound fade, showing that sound cannot travel without a medium.
Is Science Lab Supplies the manufacturer or a trader?
Science Lab Supplies manufactures this unit and is not a trader. It is made at the company's factory in Saha, Ambala, India, and every quotation is issued directly by that factory.
What precautions are needed with the bell jar?
Glass under vacuum can implode. Check the jar for cracks, keep students back behind a screen, and run every demonstration under teacher supervision only.
Related Vacuum and Air Pressure Apparatus
These four items build a complete air-pressure and vacuum topic around the bell jar: two ways of pumping, a ready-made sound-in-vacuum set and a crushing can for atmospheric pressure. All are school physics lab equipment in India and can share one quotation.
- Hand Vacuum Pump — hand-operated pump drawing 15 cm3 per stroke.
- School Vacuum-Pump Set — chamber and pump for vacuum and pressure experiments.
- Demonstration Device of an Alarm from a Clock Under a Bell — glass cage, electric bell and vacuum pump set.
- Crushing Can — tin-plate can that shows the force of atmospheric pressure.
Browse the full Physics Lab range or all physics lab equipment.
Last updated: 25 September 2026
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