The micron, officially obsolete as a term of measurement, is sometimes used by microchip and wiring manufacturers in place of micrometer, one-millionth of a meter. The micron or micrometer can also be expressed as:
- 10-6 meter
- One thousandth of a millimeter
- One 25th of a thousandth of an inch
The micron or micrometer is a unit of measure for the core in optical fiber, for which the most common diameter is 62.5 micrometers. It is also used to measure the line width on a microchip. Intel's Pentium 4 microprocessors are built using 0.18 or 0.13 micrometer line widths. AMD's Athlon uses a 0.18 line width.
A human hair is said to be about 50 micrometers wide.