tachometer

tachometer
—tachometrically /tak'euh me"trik lee/, adv. —tachometry, n.
/ta kom"i teuhr, teuh-/, n.
1. any of various instruments for measuring or indicating velocity or speed, as of a machine, a river, or the blood.
2. an instrument measuring revolutions per minute, as of an engine.
[1800-10; TACHO- + -METER]

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▪ measurement device
      device for indicating the angular (rotary) speed of a rotating shaft. The term is usually restricted to mechanical or electrical instruments that indicate instantaneous values of speed in revolutions per minute, rather than devices that count the number of revolutions in a measured time interval and indicate only average values for the interval.

      Mechanical tachometers utilize the fact that the centrifugal force on a rotating mass depends on the speed of rotation and can be used to stretch or compress a mechanical spring. A resonance, or vibrating-reed, tachometer uses a series of consecutively tuned reeds to determine engine speed by indicating the vibration frequency of the machine.

      Electrical tachometers are of several types. The eddy-current, or drag, type is widely used in automobile speedometers; a magnet rotated with the shaft being measured produces eddy currents that are proportional to angular speed. Electric-generator tachometers work by generating either an alternating or a direct current. The stroboscope, an instrument that illuminates rotating objects so that they appear to have stopped moving, can be used as a tachometer.

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Universalium. 2010.

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  • Tachometer — Tachometer: Die Bezeichnung für »Geschwindigkeits , Drehzahlmesser; Kilometerzähler« wurde im 19. Jh. aus gleichbed. engl. tachometer entlehnt. Dies ist eine Bildung des englischen Ingenieurs Bryan Donkin (1768–1855) aus griech. tachýs »schnell« …   Das Herkunftswörterbuch

  • Tachometer — Ta*chom e*ter, n. [Gr. ta chos swiftness, speed (fr. tachy s quick) + meter: cf. F. tachom[ e]tre.] An instrument for measuring the velocity, or indicating changes in the velocity, of a moving body or substance. Specifically: [1913 Webster] (a)… …   The Collaborative International Dictionary of English

  • Tachometer — (v. gr.), Instrument zum Messen der Geschwindigkeit von Maschinen, Fahrzeugen, Flüssigkeiten etc. Da man die Geschwindigkeit findet, wenn man den in einer gewissen Zeit zurückgelegten Weg durch diese Zeit dividirt, so kommt es meist blos darauf… …   Pierer's Universal-Lexikon

  • Tachomēter — (griech., Tachymeter, »Geschwindmesser«), s. Geschwindigkeitsmessung. Hydrotachometer (Hydrometer) sind Instrumente zur Bestimmung der Geschwindigkeit fließenden Wassers …   Meyers Großes Konversations-Lexikon

  • Tachometer — Tachomēter (grch.), Instrument zur Messung der Geschwindigkeiten bewegter Körper, bes. der Umdrehungszahlen rotierender Wellen, beruhen darauf, daß unter dem Einfluß der Zentrifugalkraft rotierende Massen, ähnlich den Schwungkugelregulatoren,… …   Kleines Konversations-Lexikon

  • tachometer — (n.) 1810, from Gk. tachos speed + METER (Cf. meter) …   Etymology dictionary

  • tachometer — ► NOUN ▪ an instrument which measures the working speed of an engine, typically in revolutions per minute …   English terms dictionary

  • tachometer — [ta käm′ət ər, təkäm′ət ər] n. [< Gr tachos, speed (< tachys: see TACHY ) + METER] a device that indicates or measures the rate of rotation of a revolving shaft …   English World dictionary

  • Tachometer — A tachometer is an instrument that measures the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analog dial, but digital displays are increasingly… …   Wikipedia

  • Tachometer — Wirbelstrom Tachometer (Fahrradtacho) …   Deutsch Wikipedia

  • Tachometer — Tacho; Geschwindigkeitsmesser * * * Ta|cho|me|ter [taxo me:tɐ], der, auch: das; s, : Messgerät, das die Geschwindigkeit eines Fahrzeugs anzeigt: laut Tachometer war sie nicht schneller als 50 km/h gefahren. * * * Ta|cho|me|ter 〈n. 13〉 =… …   Universal-Lexikon

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