Micrometer
Micrometer
A micrometer (en
, US colloquially mic, mike; SI symbol µm) is an SI unit of length equal to one millionth of a metre, or about a tenth of the size of a droplet of mist or fog. The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to 200 µm. The longest human chromosome, chromosome 1, is approximately 10 µm in length.
Etymology and pronunciation[edit]
The term micrometre is derived from the Greek words mikros, meaning "small", and metron, meaning "measure". The symbol for the prefix micro- is the Greek letter mu (µ). In English, the term is pronounced /maɪˈkrɒmɪtər/.
Use in science and technology[edit]
In science and technology, the micrometre is commonly used to specify the wavelength of infrared radiation, the size of biological cells and bacteria, and the diameter of wool fibres. It is also used in the field of microscopy, where it is a practical unit of measurement.
See also[edit]
References[edit]