Spot Reflecting Galvanometer
Product Code : SCL-PLE-11696
Quick Answer: The Spot Reflecting Galvanometer detects currents of the order of 10⁻⁹ A using a moving coil on a phosphor-bronze strip, with a light spot reflected from a concave mirror as a friction-free pointer.
Last updated: 18 October 2026
Key Features
- Moving coil suspended on a high-tensile phosphor-bronze strip.
- Concave mirror, lamp and lens produce a light-spot pointer on a translucent scale.
- Optical lever magnifies very small deflections.
- Electromagnetic (eddy current) damping settles the spot quickly.
- Light-shielded case with levelling screws and spirit level.
Technical Specifications
| Specification | Value |
|---|---|
| Current detected | Of the order of 10⁻⁹ A |
| Movement | Moving coil, phosphor-bronze strip suspension |
| Indicator | Light spot from concave mirror, lamp and lens |
| Scale | Translucent |
| Damping | Electromagnetic (eddy current) |
| Levelling | Levelling screws and spirit level |
| Enclosure | Light-shielded |
How It Is Used
After levelling the case, the galvanometer is connected as a null detector in bridge and potentiometer circuits or used for ballistic discharge experiments. Current through the coil turns the mirror, and the reflected spot moves along the scale; because the light beam has no mass or friction, very small currents still give a readable deflection.
Frequently Asked Questions
Why does the Spot Reflecting Galvanometer use a light spot instead of a needle?
A reflected light beam acts as a weightless, friction-free pointer, and the optical lever magnifies tiny coil movements so very small currents can be detected.
How is the Spot Reflecting Galvanometer set up?
The case has levelling screws and a spirit level, so it is levelled first before the coil is freed to swing.
Related Physics Lab Equipment
See the full physics lab equipment range, or these related galvanometers and bridge apparatus:
- Galvanometer
- Tangent Galvanometer
- Wheatstone Bridge Apparatus
- Potentiometer Apparatus
- Portable Wheatstone Bridge Apparatus
For a quotation on the Spot Reflecting Galvanometer, contact JLab India on +91-8569909696.
