Linear Measuring Instruments
LINEAR MEASURING INSTRUMENTS
Linear
measurement applies to measurement of lengths, diameters, heights, and
thickness including external and internal measurements.
The
line measuring instruments have series of accurately spaced lines marked on
them, e.g. scale. The dimension to be measured is aligned with the graduations
of the scale.
Linear
measuring instruments are designed either for line instruments, the measurement
is taken between two end surfaces as in micrometers, slip gauges etc.
The instruments used
for linear measurements can be classified as:
1.
Direct measuring instruments
2.
Indirect measuring instruments
The
direct measuring instruments are of two types:
1.
Graduated
2.
Non Graduated
·
The graduated
instruments include rules, vernier calipers, vernier height gauges, vernier
depth gauges, micrometers, dial indicators etc.
·
The
non-graduated instruments include calipers, trammels, telescopic gauges,
surface gauges, straight gauges, wire gauges, screw pitch gauges, thickness
gauges, slip gauges etc.
They can also be
classified as:
1.
Non-precision instruments such as steel rule, calipers etc.
2. Precision measuring instruments, such as
vernier instruments, micrometers, dial gauges etc.