vernier caliper

American  

noun

1. a caliper formed of two pieces sliding across one another, one having a graduated scale and the other a vernier.

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vernier caliper Scientific  

/ vûr′nē-ər /

1. A measuring instrument consisting of an L-shaped frame with a linear scale along its longer arm and an L-shaped sliding attachment with a vernier scale, used to read directly the dimension of an object represented by the separation between the inner or outer edges of the two shorter arms.

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Etymology

Origin of vernier caliper

First recorded in 1875–80