Clement and Desormes Apparatus
Product Code : LSK-H-11163
Clement and Desormes Apparatus (SKU LSK-H-11163) determines the ratio of the principal specific heats of air (γ = Cp/Cv) from a quick adiabatic expansion of compressed air held in a large glass bottle. It is used in B.Sc. heat and thermodynamics practicals and in engineering physics labs. The apparatus is a Science Lab Supplies product, manufactured at Plot 448, HSIIDC Industrial Area, Saha, Ambala, India, and supplied by the company itself to colleges, schools, tender contractors and distributors.
Specifications
Bottle capacity, cap fittings and accessories of the Clement and Desormes set are tabulated below. Put simply, a 10 litre glass reagent bottle is closed by a leak proof brass cap carrying a bent tube and two stopcocks, one for the pump and one opening to air, with a football pump and a manometer on a stand.
| Specification | Value |
|---|---|
| SKU | LSK-H-11163 |
| Vessel | Glass reagent bottle |
| Capacity | 10 litres |
| Cap | Leak proof brass cap |
| Bent tube | One, fitted in the cap |
| Pump stopcock | One, for connection to a pump |
| Air stopcock | One, for opening to air |
| Air pump | Football pump for filling air |
| Manometer | One, on a stand with scale |
| Mercury | Not included |
| Manufacturer | Science Lab Supplies, Saha, Ambala, Haryana |
| Country of origin | India |
Applications and Experiments for the Clement and Desormes Apparatus
Air is pumped into the bottle until the manometer shows a small excess pressure; once it settles, the air stopcock is opened briefly so the gas expands adiabatically, then closed. The pressure regained as the air warms back to room temperature, compared with the first reading, gives γ for air.
- B.Sc. physics practical: ratio of specific heats of air by Clement and Desormes' method, reading the pressure head on the supplied manometer or on a glass U-Tube Manometer scaled 80–0–80.
- Engineering thermodynamics: illustrating adiabatic and isothermal changes of a fixed mass of gas.
- Pressurising the bottle with the football pump or with a Hand Vacuum Pump, which can also give positive gauge pressures up to 2 atm.
Use only a small excess pressure in the glass bottle, keep it on a stable bench, and handle any mercury used in the manometer strictly under teacher supervision.
Standard Scope of Supply
The set consists of the 10 litre glass reagent bottle with its leak proof brass cap carrying the bent tube and both stopcocks, a football pump for filling air, and one manometer mounted on a stand with scale. Mercury is not included, so any manometer liquid is arranged by the laboratory.
Packing, MOQ and Lead Time
A price can be given for one set for a teaching demonstration or for several sets for a college heat lab, and the quotation spells out packing, delivery time and cost for that quantity. Spare manometers or a hand pump can be listed on the same quotation.
Science Lab Supplies, an exporter registered with an Importer-Exporter Code, is able to ship to buyers in the Philippines, Nepal, Bangladesh, Zambia, Rwanda and South Africa. Pricing requests reach the team through the contact page or the enquiry cart, while tender buyers can refer to the lab tender page.
Frequently Asked Questions
What does the Clement and Desormes Apparatus measure?
It measures the ratio of the specific heat of air at constant pressure to that at constant volume. Two manometer readings, taken before and after a brief adiabatic expansion, are enough to calculate this ratio.
Is mercury supplied for the manometer?
No. The apparatus is supplied without mercury. If your method uses mercury, fill and handle it only under teacher supervision and deal with any spill according to your institution's rules, because mercury vapour is toxic.
How is air pumped into the bottle?
A football pump is supplied for filling air. It connects to one stopcock on the brass cap, while a second stopcock opens the bottle to the atmosphere for the adiabatic expansion step of the experiment.
Is Science Lab Supplies the manufacturer or a trader?
The apparatus is manufactured by Science Lab Supplies, which assembles the brass cap fittings and manometer stand in its Saha, Ambala facility. You therefore receive the quotation from the maker, not from a trading firm.
Related Gas Law and Pressure Apparatus
These Properties of Matter items study how a fixed mass of gas responds to changes in pressure, volume and temperature, or measure the pressures involved, so they belong with a specific heat ratio experiment in the same gas-laws session and can share one quotation.
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Browse the full Heat range, the Properties of Matter range for gas-law and pressure apparatus, or all physics lab equipment.
Last updated: 9 October 2026