A vernier scale, named after Pierre Vernier, is a visual aid to take an accurate measurement reading between two graduation markings on a linear scale by using mechanical interpolation, thereby increasing resolution and reducing measurement uncertainty by using vernier acuity to reduce human estimation error. It may be found on many types of instrument measuring linear or angular quantities, but in particular on a vernier caliper, which measures lengths.
Vernier caliper scales; main at top, vernier at bottom. It reads 3.58 ± 0.02 mm by adding 3.00 mm (left red mark) on the fixed main scale to vernier 0.58 mm (right red mark). The main scale reading is that to the left of the zero on the vernier scale. The vernier reading is found by locating the best aligned lines between the two scales. The 0.02 mm engraving indicates the caliper's readability and is the "vernier constant" for this scale.
Vernier micrometer reading 5.783 ± 0.001 mm, comprising 5.5 mm on main screw lead scale, 0.28 mm on screw rotation scale, and 0.003 mm added from vernier.
Pierre Vernier was a French mathematician and instrument inventor. He was the inventor and eponym of the vernier scale used in measuring devices.
Vernier caliper scales; main at top, vernier at bottom. It reads 3.58 mm ± 0.02 mm by adding 3.00 mm (left red mark) on the fixed main scale to vernier 0.58 mm (right red mark). The main scale reading is the rightmost graduation that is to the left of the zero on the vernier scale. The vernier reading is found by locating the best aligned lines between the two scales. The 0.02 mm engraving indicates the caliper's accuracy and is the "Vernier constant" for this scale.
