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. The unit is a Science Lab Supplies manufacture from Plot 448, HSIIDC Industrial Area, Saha, Ambala, India, quoted from the factory to schools, colleges, tender contractors and distributors.
Specifications
Baseplate, jar, bell and pump options for the vacuum unit are listed in the table. In short, the glass bell jar stands on a sturdy baseplate fitted with a tap, through which air is pumped out or let back in, while a detachable battery-operated bell rings inside; a hand pump works, and an electric vacuum pump is ideal.
| Specification | Value |
|---|---|
| SKU | LSK-PL-10321 |
| Vessel | Glass bell jar |
| Base | Sturdy baseplate |
| Valve | Tap on the baseplate |
| Sound source | Detachable battery-operated bell |
| Purpose | Versatile unit for demonstrating the properties of a vacuum |
| Use with | Hand pump or, ideally, an electric vacuum pump |
| 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, followed by the pull needed to separate Magdeburg Hemispheres.
- College physics: introducing vacuum techniques and pumps, including a Hand Vacuum Pump with Pressure Gauge that reads in cm and inches of mercury.
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. A hand vacuum pump or an electric vacuum pump from the physics range can be added to the same quotation, so the demonstration is ready to run on arrival.
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 given 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. To get the bell jar and a suitable pump priced together, describe the need on the contact page or place both in the enquiry cart; tender buyers can use the lab tender page.
Frequently Asked Questions
Which pump works with the bell jar?
The unit comprises the baseplate with tap, the bell jar and the bell. It can be used with a hand pump, though an electric vacuum pump is the ideal choice, and either can be added to the quotation.
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?
Vacuum demonstration units like this are manufactured by Science Lab Supplies at its Saha, Ambala factory in India, and the company quotes and dispatches them itself rather than through a trader.
What precautions are needed with the bell jar?
Glass under vacuum can implode. Check the jar for cracks before each use, keep students at a safe distance, and run every demonstration under teacher supervision only.
Related Vacuum and Air Pressure Apparatus
These seven items build an air-pressure and vacuum topic around the bell jar: three ways of pumping, two ready-made sound-in-vacuum sets, a vacuum chamber 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, down to 50 mmHg.
- Air Pump (Vacuum Pump with Aluminium Plate) — single-barrel steel pump on a wooden base, with a stop-cock plate.
- Portable Diaphragm Type Vacuum Pump cum Air Compressor — oil-free double-stage diaphragm pump for low vacuum and low pressure.
- Bell Experiment Apparatus — 2 litre bell jar with an electric bell on binding posts, 3 to 6 V.
- Demonstration Device of an Alarm from a Clock Under a Bell — glass cage, electric bell and vacuum pump set.
- School Vacuum-Pump Set — chamber and pump for reduced-pressure boiling and vacuum fountain work.
- Crushing Can — tin-plate can that shows the force of atmospheric pressure.
Browse the full Physics Lab range, the Properties of Matter range for pumps and pressure apparatus, or all physics lab equipment.
Last updated: 22 October 2026
