VERNIER CALIPER

VERNIER CALIPER

A vernier caliper is a device that lets the user measure more with accuracy and precision than could be done unaided when reading a uniformly divided straight or circular measurement scale. It is scale that indicates where the measurement lies in between two of the marks on the main scale. Vernier is common on sexants used in navigation, scientific instruments used to conduct experiments, machinists measuring tools used to work materials to fine tolerance.

            The main use of the vernier caliper is to measure the internal and the external diameters of an object as well as the inner height of a cylinder. To measure using a vernier scale, the user first reads the finely worked fixed scale. This measure is typically between two of the scale smallest graduations. The user then reads the finer vernier scale, which measures between the smallest graduations on the fixed scale providing much greater accuracy.

            An ordinary micrometer caliper consist of the following parts namely lower jaws, upper jaws, depth probe, scroll screw, lock key, fixed scale and vernier scale or auxiliary scale.

            The lower jaws are use to measure outer smaller length of a cylinder or outer diameter of a sphere while the upper jaws are use mainly to measure the inside diameter of a cylinder. Depth probe or depth gauge is the one use in measuring internal depth of a cylinder. Scroll screw is for convenient adjustment of the auxiliary scale especially in opening and closing the caliper. Lock key is use to look or securely in place the caliper prior taking the reading. The main scale is where the main reading shall be taken while the vernier scale or auxiliary scale where the secondary reading is taken respectively for its precision.