Using Dial Calipers

Dial Calipers are an easy way of measuring your workpieces accurately. The pointer on the dial rotates once every .1" and is capable of giving you a resolution of .001". To get the most accurate measurement, take 3 measurements and compare them to ensure consistency. The best way to measure is by rotating the wheel with your thumb firmly (not too hard and not too soft.. we're talking Goldilocks here) so that the jaws grab your workpiece. Pressing too hard or too soft will result in inaccurate measurements. Rocking the calipers back and forth also helps the caliper jaws seat better on your workpiece. The caliper jaws have flat faces and should sit flat against the faces being measured. Tilting the calipers even slightly will skew your measurement.
Using and reading calipers can be tricky and require a bit of practice to get good at. When you're learning how to use calipers, it's a good idea to consult a TA to make sure you're using them properly.