Prony brake

mechanics

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Last updated

July 13, 2026

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The Prony brake is a device invented by French mathematician and engineer Gaspard de Prony in 1821. It is used to measure the power output of an engine. The device functions as a friction brake. Brake blocks are applied to a rotating wheel, and the resulting friction creates torque on a lever. A scale measures the force required to keep this lever stationary, thereby indicating the engine's power. It is also referred to as an absorption dynamometer.12

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dynamometer
A Prony brake (see figure) develops mechanical friction on the periphery of a rotating pulley by means of brake blocks that are squeezed against the wheel by tightening the bolts until the friction torque FR balances the torque WL. A water brake creates a resistance by…
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A Prony brake (see figure) develops mechanical friction on the periphery of a rotating pulley by means of brake blocks that are squeezed against the wheel by tightening the bolts until the friction torque FR balances the torque WL. A water brake creates a resistance by…
Read More

Gaspard de Prony
He invented the Prony brake (1821), a device for measuring the power developed by an engine. In the Prony brake, brake blocks are squeezed against a rotating wheel, and the friction generated at the ends of the wheel applies torque to a lever; a scale measures the force…
Read More
He invented the Prony brake (1821), a device for measuring the power developed by an engine. In the Prony brake, brake blocks are squeezed against a rotating wheel, and the friction generated at the ends of the wheel applies torque to a lever; a scale measures the force…
Read More