TB 9-5210-208-24
CALIBRATION PROCESS
6. Preliminary Instructions
a. The instructions outlined in paragraphs 6 and 7 are preparatory to the calibration
process. Personnel should become familiar with the entire bulletin before beginning the
calibration.
b. Items of equipment used in this procedure are referenced within the text by common
name as listed in table 2.
c. Unless otherwise specified, verify the result of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
Adjustments required to calibrate the TI are included in this procedure. Additional
maintenance information is contained in the manufacturers' manuals for this TI.
d. Unless otherwise specified all controls and control settings refer to the TI.
7. Equipment Setup
a. Remove TI from protective case.
b. Visually inspect TI for any damage that will affect the accuracy of measurement.
Pay close attention to the rack on dial calipers. Using a magnifying glass, inspect the rack
for missing or damaged teeth, dirt and metal chips. Inspect measurement contact surfaces
for burs, abrasion or imbedded dirt.
c. If necessary, clean TI and apply a small quantity of instrument oil.
d. Slide movable jaw along full length of beam to determine if roughness, binding, or
irregularities occur.
e. Select a clean work area and allow TI and gage blocks to stabilize at existing
temperature.
NOTE
To calibrate a TI graduated in the metric system, it will be
necessary to convert the metric reading to applicable length in
inches. Formula: 1 mm = 0.03937 inch, or 1 inch = 25.4 mm.
8. Outside Scale Vernier Calipers
a. Performance Check
(1) Close jaws of TI. Vernier scale marked "outside" should read 0.
(2) Use appropriate size gage blocks to check low-range, mid-range, and full-range
indications on TI.
(3) Lay gage block stack, firmly wrung together, on surface plate or table top with
both ends of working surfaces exposed.
