ammeter


ammeter
/am"mee'teuhr/, n. Elect.
an instrument for measuring current in amperes.
[1880-85; AM(PERE) + -METER]

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▪ measurement instrument
      instrument for measuring either direct or alternating electric current, in amperes. An ammeter can measure a wide range of current values because at high values only a small portion of the current is directed through the meter mechanism; a shunt in parallel with the meter carries the major portion.

      Ammeters vary in their operating principles and accuracies. The D'Arsonval-movement ammeter measures direct current with accuracies of from 0.1 to 2.0 percent. The electrodynamic ammeter uses a moving coil rotating in the field produced by a fixed coil. It measures direct and alternating current with accuracies of from 0.1 to 0.25 percent. In the thermal ammeter, used primarily to measure alternating current with accuracies of from 0.5 to 3 percent, the measured current heats a thermoconverter (thermocouple); the small voltage thus generated is used to power a millivoltmeter. Digital ammeters, with no moving parts, use a circuit such as the dual slope integrator to convert a measured analogue (continuous) current to its digital equivalent. Many digital ammeters have accuracies better than 0.1 percent.

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Universalium. 2010.

Look at other dictionaries:

  • Ammeter — Am me*ter, n. (Physics) A contraction of amperometer or amp[ e]remeter. [1913 Webster] …   The Collaborative International Dictionary of English

  • Ammeter — (für Amperemeter), s. Elektrotechnische Meßinstrumente …   Meyers Großes Konversations-Lexikon

  • Ammeter — Ammeter, s.v.w. Ampèremeter (s. Meßinstrumente, elektrische) …   Lexikon der gesamten Technik

  • Ammeter — Ammēter, s.v.w. Ampèremeter …   Kleines Konversations-Lexikon

  • ammeter — (n.) instrument for measuring the strength of electric currents, 1882, from AMPERE (Cf. ampere) + METER (Cf. meter) …   Etymology dictionary

  • ammeter — ► NOUN ▪ an instrument for measuring electric current in amperes …   English terms dictionary

  • ammeter — [am′mēt΄ər] n. [ AM(PERE) + METER] an instrument for measuring the strength of an electric current in terms of amperes …   English World dictionary

  • Ammeter — Amperemeter redirects here. For the unit of measurement, see Ampere meter. Demonstration model of a moving iron ammeter. As the current through the coil increases, the plunger is drawn further into the coil and the pointer deflects to the right …   Wikipedia

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  • ammeter — ampermetras statusas T sritis Standartizacija ir metrologija apibrėžtis Elektros srovės stiprio matuoklis. atitikmenys: angl. ammeter; amperemeter vok. Amperemeter, n; Strommesser, m rus. амперметр, m pranc. ampèremètre, m …   Penkiakalbis aiškinamasis metrologijos terminų žodynas


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