Hand Tool + Measuring Devices

Question 1

What type of precision measuring instruments can be used to measure the outside dimensions of aircraft parts?

Answer 1

Outside micrometers.
Vernier calipers.

Question 2

For what reasons should a micrometer be periodically calibrated?

Answer 2

Calibration may be affected by:
Having been dropped.
Spindle overtightened.
Frame may be sprung.
Worn spindle and anvil surfaces due to sliding objects between them.