Vernier scale

:For the village in the Canton of Geneva, Switzerland, see: Vernier GE.

Related Topics:
Canton of Geneva - Switzerland - Vernier GE

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A vernier scale lets one read more precisely from an evenly divided straight or circular measurement scale. It is fitted with a sliding secondary scale that is used to indicate where the measurement lies when it is in-between two of the marks on the main scale.

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It was invented in its modern form in 1631 by the French mathematician Pierre Vernier (1580-1637). In some languages, this device is called a nonius, which is the latin name of the Portuguese astronomer and mathematician Pedro Nunes (1492-1578) who invented the principle.

Related Topics:
1631 - French - Pierre Vernier - 1580 - 1637 - Pedro Nunes - 1492 - 1578

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Verniers are common on sextants, scientific instuments and machinists' measuring tools (all sorts, but especially calipers and micrometers) and on theodolites.

Related Topics:
Sextant - Caliper - Micrometer - Theodolite

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When a measurement is taken by mechanical means using one of the above mentioned instruments, the measure is read off a finely marked data scale ( the "fixed" scale, in the diagram). The measure taken will usually be between two of the smallest gradations on this scale. The indicating scale ("vernier" in the diagram) is used to provide an even finer additional level of precision without resorting to estimation.

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