How to read a vernier caliper

 

A caliper gauge is a length measuring instrument. It can be used to measure inner and outer dimensions as well as depth measurements. The measuring result is displayed in millimetres and inches. With a calliper gauge you can measure linear dimensions very quickly and easily with a high degree of precision. How to read off a caliper gauge or calliper and how it is constructed, we explain here.

 

Caliper - Design

 

The calliper has received its name because it consists of two sliding parts. In most cases it has a millimetre and an inch scale. To be able to fix the measuring result, it also has a locking screw. It also serves to be able to maintain a set dimension. On the moving part there is a scale, the so-called vernier. It is used for the exact determination of the linear measure, accurate to a tenth of a millimeter.

 

Caliper gauge - external measurement

Caliper gauge external measurement
Caliper gauge external measurement

 

The most common way to make an external measurement is with a caliper gauge. In order to obtain the most accurate result possible, it is important to ensure that the calliper gauge is positioned as cleanly as possible at a right angle to the workpiece. If you hold the calliper at an angle to the workpiece, you would get a wrong measuring result. The test object should also lie as close as possible to the rail.

Caliper gauge - inside measurement

Caliper gauge inner measurement
Caliper gauge inner measurement

 

With the two cutting edge-shaped measuring surfaces, internal dimensions can be measured. Diameters from three millimetres upwards can be measured precisely. Measuring errors occur with smaller diameters. Test probes are best suited for determining smaller diameters. You can buy them here.

Caliper gauge - depth measurement

Caliper gauge depth measurement
Caliper gauge depth measurement

 

For depth measurement the depth rod of the caliper gauge is required. The end of the caliper gauge and the end of the depth rod serve as the measuring surface. To obtain an accurate measuring result, the caliper gauge must be positioned as perpendicular to the workpiece as possible.

Example Reading caliper gauge

How to read a vernier caliper
Example Reading Caliper gauge

 

The reading mark is between 2.4 and 2.5 cm. The more accurate value 2.4 cm + 0.7 mm is due to the fact that only the seventh mark of the vernier is exactly opposite a mark of the scale. Here you can read the measurement result on the calliper.