Tachometer
lastmod 2020-04-22created 2020-04-221 edits
A tachometer (American English: Tachometer, British English: rev counter), also called a revolution counter or rotational speed meter, is a gauge or measuring instrument that indicates the number of revolutions (rotational speed) of a shaft in a machine, and is a type of revolution counter. "tacho" comes from takhos (Greek: takhos), the Greek word for speed. It is fitted to machines where shaft rotation matters, such as engines, electric motors, and generators, and can also be used by the operator to know the current revolution count. There are also tachometers as general-purpose measuring instruments for measuring the revolutions of machines that have no tachometer. This page focuses on tachometers in cars and motorcycles.