| micrometer [mī`kräm·ǝd·ǝr] ENGINEERING 1. An instrument attached to a telescope or microscope for measuring small distances or angles. 2. A caliper for making precise measurements; a spindle is moved by a screw thread so that it touches the object to be measured; the dimension can then be read on a scale. Also known as micrometer caliper. MECHANICS A unit of length equal to one-millionth of a meter. Abbreviated μm. Also known as micron (μ). |