ultramicrometer

[uhl-truh-mahy-krom-i-ter]

noun

a micrometer calibrated to a very fine scale and capable of measuring extremely small magnitudes.

Origin of ultramicrometer

First recorded in 1925–30; ultra- + micrometer1
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British Dictionary definitions for ultramicrometer

ultramicrometer

noun

a micrometer for measuring extremely small distances
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012