# Learn

What is A Vernier caliper & History behind its Invention? It is a special measuring device consisting of a fixed scale and a sliding Vernier scale on top of it, widely used to measure thicknesses and diameters of objects. The caliper contains two measuring jaws attached to these scales and an objects length is found by measuring the distance between them. Invented by French mathematician and inventor Pierre Vernier, the Vernier caliper delivers highly accurate readings due to an enhancement factor which is created because of a difference between the divisions on the Vernier scale and main scale.

Which measurements can be taken by this instrument? It can be used to measure inside and outside diameters plus the length of a step and depth of an object. To measure the outside diameter, place the object between the lower jaws and grip it firmly. Use the lock screw to fix the scales position and note the readings. The same steps apply for inside diameters but use the upper jaws instead. Steps can be measured using the head of the caliper and the right hand upper jaw. Place the sliding jaw on a steps edge and open the caliper till the right upper jaw touches the lower step and note the reading. The depth gauge lies at the end of the main beam. First rest the beam surface on the objects edge, then open the caliper till the depth gauge touches the bottom and then note the reading.

Read more about how to take these measurements: Depth, Step, Inside & Outside Measurement of Object

What Precautionary Steps to be taken when using this instrument? There are some important precautions to take while measuring objects with a vernier caliper to minimize errors. Position your eyes directly above the scale while measuring to reduce parallax error. Use consistent units to avoid calculation errors. Don’t grip the object so tightly as to cause deformation which changes the length of an object. Ensure there is no zero error by closing the jaws and noting the alignment of the zeros on the two scales. Use the on/off button in case of a digital caliper and check the LCD and all buttons to see if they are working. Lastly ensure all parts of the caliper are clean and moving smoothly.