 Another important feature on a set of digital calipers is the origin or zero button. It's similar to the tear function on a scale. It subtracts the current measurement value from subsequent measurements. Let's say you want to measure the spacing, aka pitch, between these header pins. First, measure the thickness of one pin. Set this to be the new origin for the display value. Then measure the space between the outer edges of two adjacent pins. One pin's thickness is subtracted automatically, giving us the distance between each pin's center. And that's our pin pitch. To zero out the origin, just close the jaws fully and tap the button once again.