• WordNet 3.6
    • n tachometer measuring instrument for indicating speed of rotation
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Webster's Revised Unabridged Dictionary
    • n Tachometer (Physiol) An instrument for measuring the velocity, or indicating changes in the velocity, of a moving body or substance.
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Century Dictionary and Cyclopedia
    • n tachometer An instrument for measuring velocity. Specifically— A contrivance for indicating small variations in the velocity of machines, one form of which consists of a cup and a tube opening into its center, both being partly filled with mercury or a colored fluid, and attached to a spindle. This apparatus is whirled round by the machine, and the centrifugal force produced by this whirling causes the mercury to recede from the center and rise upon the sides of the cup. The mercury in the tube descends at the same time, and the degree of this descent is measured by a scale attached to the tube. The velocity of the machine being lessened, the mercury rises in the center, causing a proportionate rise in the tube.
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Chambers's Twentieth Century Dictionary
    • n Tachometer tā-kom′e-tėr an instrument for measuring variations in the velocity of machines
    • Tachometer Also Tachym′eter
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Webster's Revised Unabridged Dictionary
Gr. ta`chos swiftness, speed (fr. tachy`s quick) + -meter,: cf. F. tachomètre,


In literature:

Associated Words: tachymeter, tachometer, trechometer, stathmograph, momentum, impetus.
"Putnam's Word Book" by Louis A. Flemming

In news:

0 The AF16 resonant vibratory drive features the tachometer feedback system found in the AF14 and AF15 drives.
2012 Jeep Wrangler Arctic Edition Tachometer Detail.
The Roadster also features dual front disc brakes, a tachometer, high-compression and high-flow heads and performance cams.
Most of today's trucks come with a tachometer already installed in the cluster, so the need for a big, massive thing bolted to the dash is kind of redundant.
Round object at bottom of window is tachometer.
The easy-to-use and read YELLOW JACKET® Tachometer unit measures 10 to 99,999 RPM on compressors, fans, motors, gears, pulleys, and more.

In science:

GONG instrument is based on a Michelson interferometer called a Fourier Tachometer (Beckers & Brown, 1978).
The Quasi-Biennial Periodicity (QBP) in velocity and intensity helioseismic observations