Definition of Micrometer

1. Noun. A metric unit of length equal to one millionth of a meter.

Exact synonyms: Micron
Generic synonyms: Metric Linear Unit
Terms within: Micromillimeter, Micromillimetre, Millimicron, Nanometer, Nanometre, Nm
Group relationships: Millimeter, Millimetre, Mm

2. Noun. Caliper for measuring small distances.
Exact synonyms: Micrometer Caliper, Micrometer Gauge
Generic synonyms: Caliper, Calliper

Definition of Micrometer

1. n. 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.

Definition of Micrometer

1. Noun. An SI/MKS unit of measure, the length of one one-millionth of a meter. Symbols: µm, um, rm ¹

2. Noun. A device used to measure distance very precisely but within a limited range, especially depth, thickness, and diameter. ¹

¹ Source:

Definition of Micrometer

1. [n -S]

Medical Definition of Micrometer

1. 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. Circular, 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 objects 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, or Bifilar, micrometer. See Bifilar. Micrometer caliper or gauge, 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. Position micrometer. See Position. Scale, 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. Origin: Micro-: cf. F. Micrometre. Source: Websters Dictionary (01 Mar 1998)

Micrometer Pictures

Click the following link to bring up a new window with an automated collection of images related to the term: Micrometer Images

Lexicographical Neighbors of Micrometer

micrometastatic disease
micrometer (current term)
micrometer caliper
micrometer gauge
micrometre disk

Literary usage of Micrometer

Below you will find example usage of this term as found in modern and/or classical literature:

1. The Principles and Practice of Surveying by Charles Blaney Breed, George Leonard Hosmer (1908)
"the micrometer readings. For any pointing of the telescope the direction is read by simply turning the micrometer until the crosshairs are placed ..."

2. The Microscope: An Introduction to Microscopic Methods and to Histology by Simon Henry Gage (1920)
"Thus, suppose with a given optical combination and tube-length it required five divisions on the ocular micrometer to include the image of 0.2 millimeter of ..."

3. A Dictionary of Science, Literature, & Art: Comprising the Definitions and by George William Cox (1866)
"In the field of the microscope is placed an ordinary stage micrometer, with the lines separated by thousandths of an inch, care being taken that tho ..."

4. The Encyclopaedia Britannica: “a” Dictionary of Arts, Sciences, Literature edited by Hugh Chisholm (1911)
"The same firm is also constructing a micrometer in which the readings of the ... The small drum-head Т opposite the micrometer head S turns a screw which ..."

5. A Practical Treatise on the Use of the Microscope: Including the Different by John Quekett (1855)
"To find the Value of the Lines in the Negative Eye-piece micrometer.—The micrometer set in its brass frame, as seen in fig. 167, is passed so far through ..."

6. Monthly Notices of the Royal Astronomical Society by Royal Astronomical Society (1866)
"With Airy's micrometer it is hardly possible to exceed the small angles that are to be measured therewith, and the errors committed in determining the ..."

7. Dyke's Automobile and Gasoline Engine Encyclopedia by Andrew Lee Dyke (1919)
"The micrometer without moves through the nut in the frame, ... When the micrometer is closed, the beveled edge of the thimble coincides with the line marked ..."

Other Resources Relating to: Micrometer

Search for Micrometer on!Search for Micrometer on!Search for Micrometer on Google!Search for Micrometer on Wikipedia!