What is "tachymeter"

Tachymeter \Ta*chym"e*ter\, n. [Tachy- + -meter.]

1. (Surveying) An instrument, esp. a transit or theodolite with stadia wires, for determining quickly the distances, bearings, and elevations of distant objects.

2. A speed indicator; a tachometer.

surveying instrument, 1836, from tachy- "swift" + -meter. Related: Tachymetry.\n\nM. GAETANO CAÏRO has invented an instrument, to which he has given the name of Tachymeter (rapid measurer). Its object is to give the area of plane surfaces bounded by any outline whatever, without the necessity of any arithmetical operation.

["Magazine of Popular Science and Journal of the Useful Arts," Volume 2, 1836]

n. 1 A surveying instrument for quickly finding distances. 2 A speed indicator; a tachometer.

n. a theodolite designed for rapid measurements [syn: tacheometer]

A tachymeter [ta-kim-i-ter, tuh-] scale is a scale sometimes inscribed around the rim of an analog watch. It can be used to compute a speed based on travel time 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.

The function performed by a tachymeter is independent of the unit of distance (e.g. statute miles, nautical miles, kilometres, metres etc.) as long as the same unit of length is used for all calculations. It can also be used to measure an industrial production process in units per hour. A tachymeter is simply a means of converting elapsed time (in seconds per unit) to speed (in units per hour).

Tachymeter may refer to:

• Tachymeter (survey) or tacheometer, a type of theodolite used for rapid measurements of distance
• Tachymeter (watch), a scale sometimes inscribed around the rim of an analogue watch

ca:Taquímetre fr:Tachymètre ja:タキメーター no:Tachymeter nl:Tachymeter ru:Тахиметр sk:Tachymeter