Dynamometer

Dynamometer, originally an instrument for measuring force, such as the pull exerted by a horse in drawing a cart; but the name is now usually given to instruments for measuring power. A friction brake, for example, applied to a drum on the shaft of a steam-engine, may be arranged so that it measures the rate at which the engine is doing work on the brake: the device then forms an absorption dynamometer. There are also various transmission dynamometers which measure the power conveyed by a belt or by a shaft without absorbing it.