TB 9-5220-212-40
CALIBRATION PROCESS USING DIFFERENTIAL ELECTRONIC LEVEL
10. Preliminary Instructions
a. The instructions outlined in paragraphs 10 and 11 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 tables 2 and 3.
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 manufacturer's manual for this TI.
d. Unless otherwise specified, all controls and control settings refer to the TI.
11. Equipment Setup
a. The following conditions must prevail before starting calibration:
(1) TI must be supported at same points used by manufacturer. If support feet are
missing, replace at points specified by manufacturer.
(2) Temperature of mass must be in equilibrium.
(3) Vibration must be excluded.
(4) TI must be clean.
b. Place differential electronic level on TI. Connect to 115 V ac power source.
c. Set amplifier MODE switch to MTR (power on) and allow 20 minutes for warm-up.
d. Position controls on differential electronic level as listed in (1) through (3) below:
(1) RANGE selector switch to 0.5.
(2) Polarity switch heads A and B to NORMAL.
(3) HEAD SELECT switch to HEAD A.
e. Level TI using differential electronic level.
12. Flatness Tolerance
a. Performance Check
NOTE
While performing this procedure, column 2 and 3 of tables 4, 5,
and 6 in section III contain the same values. This is because
differential electronic level is zeroed prior to making
measurement.
(1) Select adjustable base with support points approximately 8 percent of TI width.
NOTE
