:rolleyes: what<s a vernir calliper

A precision measuring device.

The spacing of the lines on the vernier is slightly different that the spacing of the lines on the main scale. The difference allows the user to identify the measurement to a much greater degree of accuracy than would otherwise be possible.

See the animation at Caliper - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Calipers) to see how the vernier works.

A similar system allows the user to measure to the nearest 0.0001 inch with dial calipers!