Micrometre - Wikipedia
The micrometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is an SI derived unit of length equaling 1 × 10 −6 metre (SI standard prefix "micro-" = 10 −6); that is, one millionth of a metre (or one thousandth of a ...
