Machine shops often use vernier calipers to measure parts.
Machinists and engineers use vernier calipers to make very precise measurements of manufactured parts. These devices can measure down to .0005 inches, and are ideal for measuring small parts for the automotive and aerospace industries. Although vernier calipers are not difficult to read, it does take time and a little practice to read them quickly and correctly. Once you get the hang of the reading procedure, it will soon become second nature.
Instructions
1. Unlock the slider and move it back and forth to make sure that debris or dirt will not interfere with the workings of the caliper. Push the slide all the way to the left to check the zero point. The marker should line up with the zero on the slide. If it doesn't, you can either adjust the caliper's jaws until the marker lines up with the zero, or else add the amount by which the caliper is off to the final measurement.
2. Clean the caliper's jaws and slide, along with the part you want to measure, with a clean, dry cloth before taking the measurement. This will prevent debris from causing a false reading. If there is debris on the jaws, the slide or the part, your measurement may be inexact enough to cause problems.
3. Open the jaws of the caliper wide enough to slide the part between them. Slowly close the jaws until each jaw rests on one side of the part. When measuring a round item, make sure the jaws are on either side of the item's widest point to get a proper reading.
4. Note the location of the moving slide in relation to the larger numbers on the slide itself. The number to its left is the first number. If the slide is past the "2," that is the first part of the measurement, which represents 20mm.
5. Note the mark that is just to the left of the "0" mark on the moving slide. This is the second part of the measurement. You will add both numbers to calculate the final measurement. If it is just to the right of the "5," but not quite to the "6," the next number is a five, or 5mm.
6. Look at the 10 marks on the moving slide. Locate the mark that most closely lines up with the mark on the non-moving slide just above it. This will give you the third, and final, number to add to the previous measurements. If the marks line up between the "3" and "4" marks on the moving slide, you would add .35 to the measurement.
7. Add up all of the numbers for your final measurement. In this example, you would add 20 plus 5 plus .35, resulting in a measurement of 25.35mm.
