The vernier caliper, is a measuring instrument equipped with a scale and a cursor that slides in itself. In the cursor is recorded a second scale called vernier scale or nonius. A Vernier allows a precise reading of some value. In the figure to the right, the Vernier moves up and down to measure a position on the Scale. This could be part of a barometer which reads atmospheric pressure.
Comparing to the digital vernier caliper manufacturers china, traditional manual calipers were limited by the visual acuity of the operator. A special scale was developed by French mathematician Pierre Vernier in 1631; it was designed to improve accuracy of eye-sighted calibrations. Instead of holding a scale up to an object, this device is placed in or around the object while its two scales are compared using the slightly more user-friendly process of aligning lines between scales. The sliding scale is constructed as a constant fraction of the main scale in order to make calculations easier.
