Yamaha MM700A Manual page 22

marking as a standard inch micrometer with an additional
vernier scale on the sleeve (Figure 30).
The vernier scale consists of 11 lines marked 1-9 with a
0 on each end. These lines run parallel to the thimble lines
and represent 0.000 1 in. increments.
When reading a vernier inch micrometer, perform the
following steps while referring to Figure 31.
.
1 Read the micrometer in the same way as a standard mi-
crometer. This is the initial reading.
2. If a thimble mark aligns exactly with the sleeve line,
reading the vernier scale is not necessary. If they do not
align, read the vernier scale in Step 3.
STANDARD INCH MICROMETER
Sleeve line
. . . . .
Thimble
Sleeve
I
1. Largest number visible on the
2.
3. Thimble mark that aligns with
Ratchet
sleeve line
Number on sleeve marks visible
between the numbered sleeve mark
and the thimble edge
sleeve line
Total reading
3. Determine which vernier scale mark aligns with one
thimble mark. The vernier scale number is the amount in
ten-thousandths of an inch to add to the initial reading
from Step 1.
Metric micrometer
The standard metric micrometer (Figure 32) is accurate
to one one-hundredth
o f
sleeve line is graduated in millimeter and half millimeter
increments. The marks on the upper half of the sleeve line
equal 1 . O O mm. Every fifth mark above the sleeve line is
0.200 in.
0.025 in.
0.231 in.
a millimeter (0.01-mm). The