How to Use a Vernier Caliper

When highly accurate measurements are needed from a measuring device such as a micrometer, a sliding scale, called a Vernier scale, is used in addition to the usual fixed scale. The Vernier scale refines the accuracy of the measurements by further dividing the lowest subdivision on the fixed scale of a caliper micrometer. For instance, if the smallest increment on the fixed scale was 0.25 mm, then the Vernier scale would have a range of 0.0 to 0.25 mm.

Things You'll Need

• Vernier caliper
• Object to measure

Instructions

Using Vernier Calipers

1. Open the calipers slightly more than the size of the object you are measuring.

2. Use the adjustment device, usually a thumb wheel, to close the calipers until they are just touching the object. If your calipers have a fine adjustment device, use it to close the calipers until the calipers can hold the object in place. Do not over-tighten, as this will give an inaccurate measurement or damage the calipers.

3. Use the locking device on the calipers to hold the measurement in place. The locking device may be another thumb wheel or a thumb lever.

4. Read the measurement on the fixed scale and the Vernier scale. Combine the measurements to get the total measurement for the object.