Tachymeter : Tachometer

The tachymeter is also a function that is directly correlated to the use of an inner or outer bezel on the watch. To do so, start the chronograph function of the watch at a mile indicator. At the next mile indicator, the point on the scale that is adjacent to the second hand is your MPH speed. The tachymeter is a way of projecting the units travelled per hour.

3345, Watches Australia.