Spherometer-Double Disc
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Product Code : SCL-PLE-11650
Quick Answer: The Spherometer-Double Disc measures the radius of curvature of lenses and curved mirrors, and the thickness of thin plates. It stands on three hardened steel legs around a 50mm machined table, with a 100-division circular disc scale read against a vertical scale.
Last updated: October 2026
Key Features
- Least count 0.01 mm
- Three black-enamelled hardened carbon steel legs as contact points
- 50mm machined circular table
- Fine-pitch steel screw in an adjustable brass housing
- Vertical linear scale plus a 100-division circular disc scale
- Double disc for finer control when finding the point of contact
Technical Specifications
| Specification | Value |
|---|---|
| Materials | Machined brass bearings; hardened carbon steel tripod legs |
| Table diameter | 50mm |
| Legs | Three black-enamelled steel contact points |
| Mechanism | Fine-pitch steel screw, adjustable brass housing |
| Scales | Vertical linear scale and 100-division circular disc scale |
| Least count | 0.01 mm |
| HS code | 9017.30.00 |
About This Product
Students set the spherometer on a flat glass plate to take a zero reading, then on the curved surface, and use the difference (the sagitta) with the leg spacing to calculate the radius of curvature. The same screw reading gives the thickness of a thin glass slip or plate, and the practical is a good exercise in least count and measurement uncertainty. Schools, colleges and institutes in United Arab Emirates, Estonia, South Africa, Peru, Serbia and Gabon can order the Spherometer-Double Disc from Educational Instrument.
Frequently Asked Questions
What can the Spherometer-Double Disc measure?
The radius of curvature of spherical surfaces such as lenses and mirrors, and the thickness of thin plates, to a least count of 0.01 mm.
Related: Physics Lab Equipment and Spherometer-Disc Type.
For a quotation on the Spherometer-Double Disc, contact Educational Instrument.
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