Lesson 1/Learning Event 2
Use the following sequence to read the measurement shown in Figure 7.
a. Highest figure visible on barrel.
2 = 0.200 inch
b. Number of lines visible between
the No. 2 and thimble edge.
1 = 0.025 inch
c. Line on the thimble that coincides
with or has passed the revolution
or long line on the barrel.
16 = 0.016 inch
d. Measurement reading
Total = 0.241 inch
The same principal applies to reading metric graduated micrometers.
the following changes in graduation should be noted to avoid confusion:
a. The pitch of the metric micrometer screw is 0.5 millimeter (mm).
One revolution of the spindle advances or withdraws the screw a
distance equal to 0.5 mm.
b. The barrel is graduated in millimeters, from 0 to 25.
It takes two
revolutions of the spindle to move 1 mm.