Caliper - Vernier Scale and Other Types of Calipers
A caliper or a pair of calipers is a measurement tool that is used to
measure the distance between two opposite sides of an object. Calipers
usage is very wide: from medicine, science, mechanical engineering,
woodworking metalworking to forestry.
People are using calipers some two thousand and six hundred years ago in
ancient Greece. The oldest calipers are the one that was found near the
Italian island Giglio in the ship from sixth century BC. Those calipers
were wooden. Greeks and also Romans were using calipers. Another caliper is
found in China dating from 9 AD during the Chinese Xin Dynasty. Joseph R.
Brown invented the modern caliper. That caliper was invented in 1851, and
it could read to thousandths of an inch. It was also a very cheap tool
which means that ordinary machinist could afford it.
Types of Calipers
There are a few types of a calipers. Most popular are:
An inside caliper is a measurement tool used for measuring
internal size of an object. It can be adjusted manually with the screw.
Unlike inside calipers, there are outside calipers, and
they are used to measure the external size of an object. This tool can give
a high level of accuracy. It works similarly like inside caliper with and
without the screws. This kind of calipers is usually made from high carbon
Another type of calipers is a divider caliper or a compass
which is a popular name for it. A divider caliper is used for marking out
is a type of caliper that is used to draw a line a set distance from the
edge of a workpiece.
is a measuring instrument which can measure with a huge precision. Vernier
scale is used in navigation, by scientists, machinists, and surveys. The
other name for a vernier scale is a nonius which was commonly used in the
English language by the eighteenth century.
One of the primary usages of vernier scale is a measurement of external
diameters, internal diameters and a depth of an object. When measuring with
the vernier scale, user first must read the fixed scale and then must read
the finer scale for the most accurate result of measuring. It can show the
results of a measuring with the accuracy up to two decimals.
One of the main reasons why vernier scales work so good is because of the
ability of most people to detect which of the lines is aligned and which is
not. This ability can even improve with the practice. The name of his
ability is vernier acuity and because of it, the vernier scale has
advantage comparing to other measuring devices.
Other Types of Calipers
A dial caliper is a type of caliper which has a simple
dial instead of a vernier mechanism. That dial is used for reading the
final fraction of a millimeter or inch. The dial rotates once per every
inch or millimeter.
is also a type of caliper but with the digital display which gives the
information about the precise result of a measuring by showing the numbers
One of the calipers that use a screw for measurement rather than a slide is
called a micrometer.