- Make sure that whatever you are measuring is clean and has no burrs on the edges.
- Open the jaws of the caliper and position them on both sides of the piece you are measuring.
- On the vernier scale is a small number 0. Look at how many inch divisions it is past on the bar scale.
- See how many smaller (numbered) divisions the small 0 has gone past. This represents how many tenths of an inch the work piece is measuring in addition to the number of whole inches
- How many smaller divisions has the small 0 gone past the last numbered division, this number multiplied by 25 is how many hundredths of an inch.
- Determine which division line on the vernier scale best lines up with a division on the bar scale
- By adding the inch measurement, the tenths of an inch, the hundredths, and the thousandths, you will have a measurement to a 3 decimal place accuracy.