Definition of the vernier caliper
What is a vernier caliper ? A vernier caliper is a measuring
instrument which can make inside, outside, or depth measurements.
The vernier scale on it is marked in both British Imperial and
metric divisions. The vernier scale has a stationary scale and a
movable scale, in this case the vernier bar to the vernier plate.
The length is read from the vernier scale.
The movable scale on the vernier caliper is parallel to the fixed
scale. These high precision measuring instruments are able to
measure outside and inside diameters and most will even measure
depth. There are both Imperial and metric scales. The main scale of
the caliper is divided into 10 parts, each equal to 0.100 inch. The
area between the 0.100 marks is divided into four. Each of these
divisions is equal to 0.025 inches.
There are 25 divisions on the vernier scale, each one representing
0.001 inch. Measurement readings are taken by combining the main and
vernier scales. Only one division line on the main scale will always
line up with a line on the vernier scale. This is the basis to
ensure accurate measurements.
To read the caliper, locate the line on the main scale that lines up
with the zero (0) on the vernier scale. If the zero lined up with
the 1 on the main scale, the reading would be 0.100 inches. If the
zero on the vernier scale does not line up exactly with a line on
the main scale, then look for a line on the vernier scale that does
line up with a line on the main scale.