In various electrical applications, a dynamometer is a measuring instrument in which a pointer is deflected as a result of the force exerted between fixed and moving coils, the pointer being attached to the latter. It has applications in ammeters, wattmeters, and voltmeters.
Various types of mechanical dynamometer are used to measure the power output of a machine or of the force of muscular contraction. A small hand-held dynamometer may be used to record the strength of a patient's grip. A special optical dynamometer measures the actions of the muscles controlling the shape of the lens of the eye. The term torque meter is used to describe a device for measuring the power of rotating engines.