Category:Tachometer

Ta*chom"e*ter, n. Etym: [gr. -meter: cf. F. tachomètre.]

Defn: an instrument for measuring the velocity, or indicating changes In the velocity, of a moving body or substance. Specifically: -- (a) an instrument for measuring the velocity of running water in a River or canal, consisting of a wheel with inclined vanes, which is Turned by the current. The rotations of the wheel are recorded by Clockwork. (b) an instrument for showing at any moment the speed of a revolving Shaft, consisting of a delicate revolving conical pendulum which is Driven by the shaft, and the action of which by change of speed moves A pointer which indicates the speed on a graduated dial. (c) (physiol.) An instrument for measuring the velocity of the blood; A hæmatachometer.