He watched his tachometer, which indicated his revolutions per minute.
His clock and his tachometer assured him that he was well past Easton.
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.
It is driven by a 220-volt motor connected to a tachometer which reads both meters per second and revolutions per minute.
The engine was next started and the number of revolutions of the propellers counted by a tachometer.
It had been suggested that the revolutions in Africa occurred so often that only a tachometer could keep up with them.
1810, from Greek tachos "speed" + -meter.
tachometer ta·chom·e·ter (tā-kŏm'ĭ-tər, tə-)
n.
An instrument used to measure the rotations per minute of a rotating shaft.
