| watchm. |
tachymeter (A tachymeter (pronounced /tæˈkɪmətər/) is a scale sometimes inscribed around the rim of an analog watch with a chronograph. It can be used to conveniently compute the frequency in hours of an event of a known second-defined period, such as speed (distance over hours) based on travel time (seconds over distance), or measure distance based on speed. The spacings between the marks on the tachymeter dial are therefore proportional to 1⁄t, where t is the elapsed time. NOT TO BE CONFUSED WITH: ТАХОМЕТР и ТАХЕОМЕТР  wikipedia.org) |
