Each scale of your caliper reads like an ordinary ruler. The major scale is fixed in place, while the Vernier scale is the name for the sliding scale that opens and closes the jaws. A Vernier caliper has primary jaws used for measuring the external diameter and smaller jaws used for measuring the internal diameter of objects. Understand the parts of the Vernier caliper. How to Use a Vernier Caliperīelow is a step by step explanation for using Vernier calipers Preparing Your Instruments and Tools Keep reading to learn how to read vernier caliper in cm and inches. It allows you to take more precise measurements than regular rulers. Calipers are measuring tools used to precisely determine the width of a gap or object, much more accurately than a tape measure or ruler.Ī Vernier caliper is an instrument that measures internal or external dimensions and distances. Are you looking to do a DIY project and need accurate measurements? Then you need to use vernier calipers.