Stefan Boltzmann Apparatus Manufacturer,Supplier and Exporter in India
Product Code : EL-HTL-10049
Jlab Export is a leading Stefan Boltzmann Apparatus Manufacturer,and suppliers in India
Stefan Boltzmann Apparatus (code EL-HTL-10049) is a radiation set-up for determining the Stefan-Boltzmann constant: a blackened 20 mm copper disc is inserted at the centre of a 200 mm copper hemisphere kept hot by a 250 mm water jacket, and the rate at which the disc warms gives σ. A buzzer timer sounds every 5 seconds for the disc readings. The copper hemisphere, water jacket and test disc are made by JLab in Ambala, India.
Specifications
| Parameter | Detail |
|---|---|
| Hemisphere | Copper sheet, 200 mm diameter |
| Water jacket | 250 mm diameter, surrounding the hemisphere |
| Hot water supply | Water heating tank with an electric immersion heater |
| Test disc | Copper, 20 mm diameter, blackened, with a thermocouple at its centre |
| Temperature indicator | Multichannel digital, 0–200 °C, least count 0.1 °C, for hemisphere and disc |
| Timer | Audible buzzer sounding every 5 seconds |
| Supplied with | Technical manual |
| Electricity | 230 V, 15 A AC, with earthing |
| Bench area | About 1 m x 0.5 m at working height |
| Quality check | Each radiation apparatus is visually inspected before dispatch |
| Pack quantity | Each (sold individually) |
| Minimum order quantity | 1 unit |
| Dispatch time | Usually 14–18 working days |
| Product code | EL-HTL-10049 |
| Manufacturer | Jain Laboratory Instruments Pvt Ltd (JLab) — OEM |
| Country of origin | India (made in Ambala, Haryana) |
From Disc Warming Rate to σ
Hot water from the immersion-heated tank fills the jacket until the hemisphere settles at a steady temperature Th. The disc, still at room temperature Td, is then inserted and its centre thermocouple is read at each buzzer signal. Over the first few readings, radiation from the hemisphere is practically the only heat reaching the disc, so the energy balance is m c (dTd/dt) = σ A (Th⁴ − Td⁴), with m and c the mass and specific heat of the copper disc and A = πd²/4 its exposed face. The slope of the temperature–time plot at the moment of insertion then gives σ = m c (dTd/dt)/[A(Th⁴ − Td⁴)], all temperatures in kelvin.
Why the Timer and 0.1 °C Resolution Matter
The useful part of the record is short, because the balance holds most closely while the disc is still near room temperature. The buzzer keeps the readings evenly spaced at 5 seconds, and the 0.1 °C least count resolves the small rise between them, so the initial slope can be drawn from a handful of points. Results are judged against the textbook figure for σ of about 5.67 × 10⁻⁸ W/m²K⁴.
Other Radiation Set-ups
- Stefan Boltzmann Apparatus — hemisphere on a Bakelite plate, heated from a hot water tank mounted above it.
- Emissivity Measurement Apparatus — test plate and identical blackened plate, each with a mica heater, in a glass-sided enclosure.
- Combined Convection and Radiation — heated horizontal cylinder in a vertical air duct with a variable airflow.
More radiation and conduction rigs are in Heat Transfer Lab, part of Engineering Lab Equipment.
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Last updated: 30 October 2026
