It is driven by a 220-volt motor connected to a tachometer which reads both meters per second and revolutions per minute.
He watched his tachometer, which indicated his revolutions per minute.
It had been suggested that the revolutions in Africa occurred so often that only a tachometer could keep up with them.
I guess the first thing that Lindy watched was the tachometer.
There is a gear which serves to drive the magnetos and tachometer, also the air pump.
A tachometer was also employed to observe the number of turns that the screw was making in a minute.
His clock and his tachometer assured him that he was well past Easton.
The engine was next started and the number of revolutions of the propellers counted by a tachometer.
tachometer ta·chom·e·ter (tā-kŏm'ĭ-tər, tə-)
An instrument used to measure the rotations per minute of a rotating shaft.