Micrometre
A micrometre (American spelling: micrometer), symbol µm, is an SI unit of length. It is defined as one millionth of a metre (1×10−6 m), equivalent to one thousandth of a millimetre.
The symbol µ (Unicode character U+00B5; HTML µ) is the "micro sign"; it is derived from the Greek letter mu (μ). The symbol "um" is sometimes used, when the µ and μ are not available, e.g. when using a typewriter. The micrometre is a common unit of measurement for wavelengths of infrared radiation.
Some people (especially in astronomy and the semiconductor business) use the old name micron and/or the solitary symbol µ for the same thing, even though it is officially discouraged.
nanometre << micrometre << millimetre
See also
- 1 E-6 m (a list of objects on the order of one to ten micrometres)
- Micrometer, a tool that measures the thickness of objects.
