TM 9-243
READING A VERNIER CALIPER - Continued
Most vernier calipers read “OUTSIDE” on one side and
“INSIDE” on the other side. If a scale isn’t marked, and
you want to take an inside measurement, read the scale
as you would for an outside diameter. Then add the
measuring point allowance by referring to manufac-
turer’s instructions or the following table.
Size of
English
Metric
Caliper
Measure
Measure
6 inch or 150 mm
Add 0.250 inch
Add 6.35 mm
12 inch or 300 mm
.300 inch
7.62 mm
24 inch or 600 mm
.300 inch
7.62 mm
36 inch or 600 mm
.500 inch
12.70 mm
READING A METRIC CALIPER
The steel rule (1) is divided into centimeters (cm) (2) and
the longest lines represent 10 millimeters each. Each
millimeter is divided into quarters.
The vernier scale (3) is divided into 25 parts and is
numbered 0, 5, 10, 15, 20 and 25.
Read the total number of
millimeters (4) to the
left of the vernier
zero index (5) and record
. . . . . . . . . . . . .32.00 mm
Read the number of quarters (6)
between the millimeter mark
and the zero index and record
. . . . . . . . .25 mm =
(1 quarter)
Read the highest line on
the vernier scale (3) which
lines up with the line on
the scale (7) and record
. . . . . . . . . . . . . .
.18 mm
TOTAL
32.43 mm
CARE OF CALIPERS
1.
Store calipers in separate containers provided.
2.
Keep graduations and markings on all calipers
clean and legible.
3.
Do not drop any caliper. Small nicks or scratches
can cause inaccurate measurements.
4.
Protect caliper points from damage.
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