Radiometer
Product Code : EL-PLE-13194
Eduscope India is a leading Radiometer
Quick Answer: Radiometer spins a 4-vane rotor inside a partial-vacuum glass bulb using nothing but light, giving a striking visual demonstration of differential heating.
The Radiometer is a classic demonstration instrument from our physics lab equipment India range, designed to show how light can be converted into visible rotational motion. Housed in a glass bulb under partial vacuum, it uses a delicately balanced rotor to reveal the effects of differential heating in a simple, striking way. It makes a popular addition to physics laboratories and demonstration areas for teaching the relationship between light, heat and motion.
Construction
The instrument is made from a glass bulb from which much of the air has been removed, leaving a partial vacuum inside. Mounted on a low-friction spindle at the centre of the bulb is a rotor with 4 vanes. Each vane is finished with one blackened side and one silvered side, and one of the black vanes carries a white dot so that its rotations can be counted easily during observation.
How It Works
When the bulb is exposed to sunlight or artificial light, the vanes turn with no apparent motive power connecting them to an outside source. This rotation is caused by differential heating of the black and silvered vane surfaces: the blackened side absorbs more light and heats up faster than the reflective silvered side, and this imbalance within the partial vacuum sets the rotor spinning. The demonstration offers a simple, visual introduction to how light energy relates to heat and motion.
Technical Specifications
| Specification | Value |
|---|---|
| Overall Dimensions | 6" x 4" x 4" |
| Rotor Vanes | 4, blackened on one side, silvered on the other |
| Housing | Glass bulb, partial vacuum |
EduScope India's physics equipment, including this Radiometer, is exported to East African markets such as Kenya, Tanzania, Uganda and Rwanda, supporting school and college lab equipping in the region.
This instrument is also among the physics lab equipment India EduScope India regularly supplies through bulk institutional and government lab-equipment orders, school chains and CSR-funded science-education programs.
Related Instruments
For another instrument exploring heat effects in the classroom, the Heat Conductometer lets students compare thermal conductivity across different metals, complementing the light-driven heating shown here.
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