Micrometer
Micrometer Mi*crom"e*ter, n. [Micro- + -meter: cf. F. microm[`e]tre.] An instrument, used with a telescope or microscope, for measuring minute distances, or the apparent diameters of objects which subtend minute angles. The measurement given directly is that of the image of the object formed at the focus of the object glass. [1913 Webster]

{Circular micrometer}, or {Ring micrometer}, a metallic ring fixed in the focus of the object glass of a telescope, and used to determine differences of right ascension and declination between stars by observations of the times at which the stars cross the inner or outer periphery of the ring.

{Double image micrometer}, a micrometer in which two images of an object are formed in the field, usually by the two halves of a bisected lens which are movable along their line of section by a screw, and distances are determined by the number of screw revolutions necessary to bring the points to be measured into optical coincidence. When the two images are formed by a bisected object glass, it is called a divided-object-glass micrometer, and when the instrument is large and equatorially mounted, it is known as a heliometer.

{Double refraction micrometer}, a species of double image micrometer, in which the two images are formed by the double refraction of rock crystal.

{Filar micrometer}, or {Bifilar micrometer}. See under {Bifilar}.

{Micrometer caliper} or {Micrometer gauge} (Mech.), a caliper or gauge with a micrometer screw, for measuring dimensions with great accuracy.

{Micrometer head}, the head of a micrometer screw.

{Micrometer microscope}, a compound microscope combined with a filar micrometer, used chiefly for reading and subdividing the divisions of large astronomical and geodetical instruments.

{Micrometer screw}, a screw with a graduated head used in some forms of micrometers; turning the head one full revolution advances the position of the tip of the screw only by a little.

{Position micrometer}. See under {Position}.

{Scale micrometer}, or {Linear micrometer}, a minute and very delicately graduated scale of equal parts used in the field of a telescope or microscope, for measuring distances by direct comparison. [1913 Webster]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • micrometer — micrometer1 [mī kräm′ət ər] n. [Fr micromètre: see MICRO & METER] 1. an instrument for measuring very small distances, angles, diameters, etc., used on a telescope or microscope 2. MICROMETER CALIPER micrometer2 [mī′krō mēt΄ər] n …   English World dictionary

  • micrometer — (n.) 1660s, from MICRO (Cf. micro ) + METER (Cf. meter). Originally a telescope attachment; from 1884 as a craftsman s fine measuring tool. Related: Micrometry; micrometric …   Etymology dictionary

  • micrometer — ► NOUN ▪ a gauge which measures small distances or thicknesses …   English terms dictionary

  • Micrometer — This article is about the measuring device. For the unit of length, see Micrometre. Outside, inside, and depth micrometers A micrometer (   …   Wikipedia

  • micrometer — [1] A precision measuring tool that will give readings accurate to 0.002 mm or 0.0001 of an inch. Sometimes called inside micrometer or outside micrometer. Also called a mike. [2] A unit of measurement of thickness which is equal to one… …   Dictionary of automotive terms

  • micrometer — he·lio·micrometer; micrometer; ra·dio·micrometer; stereo·micrometer; ul·tra·micrometer; …   English syllables

  • micrometer — micrometer1 /muy krom i teuhr/, n. 1. any of various devices for measuring minute distances, angles, etc., as in connection with a telescope or microscope. 2. Also called mike, micrometer caliper. a precision instrument with a spindle moved by a… …   Universalium

  • micrometer — mikrometras statusas T sritis Standartizacija ir metrologija apibrėžtis Ilginių matmenų matuoklis, veikiantis sraigto principu. atitikmenys: angl. micrometer; micrometer calliper vok. Mikrometer, n; Schraubenmikrometer, n rus. микрометр, m pranc …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • micrometer — mikrometras statusas T sritis Standartizacija ir metrologija apibrėžtis Tikslus vidmatis ar išormatis, turintis smulkiasriegį sraigtinį mechanizmą, kuris stumia matavimo veleną su skale, o iš skalės rodmenų nustatoma matuojamojo dydžio vertė.… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • micrometer — /maɪˈkrɒmətə / (say muy kromuhtuh) noun 1. any of various devices for measuring minute distances, angles, etc., as in connection with a telescope or microscope. 2. a U shaped gauge for measuring thicknesses or short lengths in which the gap… …   Australian English dictionary

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