Steps for using the vernier calipers

It is very important for us to use the vernier caliper correctly to ensure an accurate measurement.Thus,here are the steps for using the vernier caliper correctly.
1. Determine that this is the best instrument you have available for the particular measurement. Do not use simply because it is handy.
2. Completely clean both the parts and the caliper. (Keep it as a good habit to automatically check all contact surfaces of the part and the instrument for burrs or other obstructions.)
3. Loosen the clamping screws on both the movable jaw and the nut carrier.
4. Set the movable jaw slightly larger than the feature to be measured.
5. Clamp nut carrier to the beam. Snug up but do not lock the clamping screw on the movable jaw.
6. Place the fixed jaw in contact with the reference point of the part feature.
7. Align the beam of the caliper to be as nearly parallel to the line of measurement as possible--in both planes.
8. Turn the adjusting nut so that the movable jaw just touches the part. Tighten clamp screw on the movable jaw without disturbing the feel between the caliper and the part.
9. If possible,read in place without disturbing part of the caliper. If not, remove the caliper.
10. Record the reading on scratch paper, chalk on part, or on part drawing. Do no trust memory.
11. Repeat the measurement steps a sufficient number of times to rule out any obviously incorrect readings and average the others for the desired measurement.
12. Loosen both clamps, slide movable jaw open, remove work, if not already done.
13. Clean, lubricate and replace instrument in its box.
14. Ask yourself, what errors may remain in your measurement.