For specific instructions on how to take
measurements with a dial/vernier caliper, refer to either
the manufacturers instructions or to Tools and Their
Uses, NAVEDTRA 10085-B2.
Regardless of what type of caliper you use, be sure
to take the following precautions to avoid damaging the
1. Wash your hands before you handle the vernier
caliper to remove dirt and oils that might damage the
2. Wipe the caliper components clean both before
and after you use the caliper.
3. Do NOT drop or otherwise mishandle the
caliper. Doing so may damage or destroy the caliper.
Figure 2-3 illustrates the use of a dial/vernier caliper
in measuring the inside and outside diameters of two
Figure 2-3.Measuring (A) inside and (B) outside diameters
with a dial/vernier caliper.
The micrometer is a precision measuring instrument
used to measure distances between surfaces in
thousandths of an inch Figure 2-4 shows the most
common types of micrometers.
Most micrometers have a frame, anvil, spindle,
sleeve, thimble, and ratchet stop.
Micrometers are used to measure the outside
diameters; inside diameters; the distance between
parallel surfaces; the depth of holes, slots, counterbores,
and recesses; and the distance from a surface to some
recessed part. There are other uses of micrometers, but
those mentioned here are uses you are most likely to
encounter. Instructions on how to read a micrometer are
given in the manufacturers owners manual and Tools
and Their Uses, NAVEDTRA 10085-B2.
Whenever you use a micrometer, carefully observe
the DOs and DONTs in the following list to obtain
accurate measurements and to protect the instrument:
Figure 2-4.Common types of micrometers.