Micrometer, << MY kroh `mee` tuhr, >> also called micron, is a metric unit of length. One micrometer is equal to 0.000001 meter, or 1/25,400 inch. The micrometer is used to express extremely short distances and the thickness of very thin objects. Scientists express the size of asbestos fibers, colloidal particles, and various other tiny objects viewed under a microscope in micrometers.
