Quick Answer: Kater’s Reversible Pendulum is a bar pendulum with two knife edges and two sliding weights, used to measure the local acceleration due to gravity. The polished steel or brass bar is nominally 120–150 cm long.
Last updated: October 2026
Key Features
Polished steel or brass bar; non-magnetic versions available
Two hardened, ground alloy steel knife edges with adjustable position
Two sliding weights, one steel and one brass, to shift the centre of gravity
Wall-mounting bracket or floor stand support
Nominal length 120–150 cm
Technical Specifications
Specification
Value
Bar
Polished steel or brass, 120–150 cm (nominal)
Knife edges
Hardened, ground alloy steel, adjustable
Sliding weights
Two: steel and brass
Support
Wall bracket or vertical floor stand
About This Product
The pendulum is swung from one knife edge and then reversed onto the other, and the weights are moved until both periods are equal. The distance between the knife edges then equals the length of the equivalent simple pendulum, which gives g without needing to locate the centre of gravity. The Kater's Reversible Pendulum can be supplied on export terms to Latvia, Guyana, Maldives, Solomon Islands and South Korea.
Frequently Asked Questions
Why does Kater’s Reversible Pendulum have two knife edges?
It is swung from each knife edge in turn. When the periods match, the knife-edge separation equals the equivalent simple pendulum length, which is used to calculate g.
