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 manufacturer's
instructions or the following table.
Size of caliper
English
Metric
measure
measure
6 in or 150 mm
Add 0.250 in
Add 6.35 mm
12 in or 300 mm
.300 in
7.62 mm
24 in or 600 mm
300 in
7.62 mm
36 in or 600 mm
.55 in
12,70 mm
OTHER CONFIGURATIONS
Other configurations of vernier calipers are available.
The rule (1) scale can be graduated increments other
than 0.025 of an inch. Likewise the vernier scale (3) can
be divided into one more part than the rule (1) scale
within the same length. The difference in width between
one space on the vernier scale (3) and one space on the
rule (1) scale Is 0.001 inch.
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 usually divided into 25 parts and
is numbered 0, 5, 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
4. can cause inaccurate measurement. Protect caliper
points from damage.
Change 3 6-5(6-6 blank)
