TM 9-243
READING A VERNIER MICROMETER
Reading the vernier micrometer is the same as reading
the standard micrometer. An additional step must be
taken, to add the vernier reading to the dimensions. This
allows for precise measurements which are accurate to
ten-thousandths (0.0001) of an inch. This scale fur-
nishes the fine readings between the lines on the thim-
ble rather than making an estimate as you would on a
standard micrometer.
The ten spaces on the vernier (1) are equivalent to 9
spaces on the thimble (2). Therefore, each unit on the
vernier scale is equal to 0.0009 inch and the difference
between the sizes of the units on each scale is 0.0001
inch.
TO READ A MEASUREMENT AS SHOWN ABOVE:
Read highest figure
visible on barrel (3). . . . . . . . . . . . . . .
Number of lines visible
between the No. 2 and
thimble edge (4). . . . . . . . . . . . . . . . .
The line on the thimble
that coincides with or
is nearest the
2 = 0.200 in.
3 = 0.075 in.
revolution or long line
in the barrel (5) . . . . . . . . . . . . . . . 11 = 0.011 in.
The line on the vernier
scale that coincides
with the line on the
thimble (6) . . . . . . . . . . . . . . . . . . . . . . .2 = 0.0002 in.
TOTAL
= .2862 in.
7-5
