## – Metric, Imperial Decimal & Imperial Fractions.

Today on Repairs101 I’m going to show you how to read the three most common types of Vernier Scale caliper.

These are the calipers I’ve collected to represent the three Vernier scales.

Now a digital caliper is easier, more accurate and way more fun to use. But a Vernier scale doesn’t need batteries.

A Vernier scale is a movable scale running parallel to a fixed scale. They measure very accurately in metric, imperial decimal and imperial fractions.

Calipers measure three different ways: outside measurements, inside measurements and depth measurements.

Now if you have a lot of nearly identical things to measure. You might find that this fine adjustment screw makes the job easier. By anchoring at a point that’s within reach of the target area. Then all you need is the fine adjustments to find each individual measurement.

To read this in metric we look at the lower fixed scale. The Vernier’s zero is just over one centimetre. So we go across the Vernier scale to see where the lines match up exactly.

This is an oil pump gear. And to find the size of the shaft that drives it you just take an inside measurement.

On this calliper, if you’re looking for an imperial decimal measurement you look at the upper scales. Ignoring the lower metric scales and you see that a US quarter measures zero point nine five inches.