Also, vernier scale. a small, movable, graduated scale running parallel to the fixed graduated scale of a sextant, theodolite, barometer, etc., and used for measuring a fractional part of one of the divisions of the fixed scale.
Machinery. an auxiliary device for giving a piece of apparatus a higher adjustment accuracy.
equipped with a vernier: a vernier barometer.
Pierre [pyer] /pyɛr/ (Show IPA), 1580–1637, French mathematician and inventor.
a small movable scale running parallel to the main graduated scale in certain measuring instruments, such as theodolites, used to obtain a fractional reading of one of the divisions on the main scale