TB 9-6625-086-35
5
SECTION IV
CALIBRATION PROCESS
NOTE
Unless otherwise specified, verify the results of each test and
take corrective action whenever the test requirement is not
met before continuing with the calibration.
NOTE
When indications specified in paragraphs
through
11
are not
within tolerance, perform the oscillator frequency check in
and the power supply check in paragraph
before making adjustments. Do not perform the procedures in
13
if all other parameters are within
tolerance.
NOTE
Remove top and side covers from the TI only for adjustment.
When adjustment is completed, reinstall the covers.
8. Coarse Null
a. Performance Check
(1) Position the TI RANGE switch to the .01 MW position.
(2) Adjust the TI ZERO controls for a 25 to 75 percent indication on the TI meter.
(3) Turn the RANGE switch to NULL.
(4) Adjust the NULL, control for minimum indication on the TI meter.
(5) Repeat (2) through (4) above until the TI meter pointer is within the NULL
region. If the meter pointer does not indicate within the NULL region, perform
b
below.
NOTE
During maintenance calibration, if a 100-ohm thermistor
mount is
not available, disregard (6) through (8) below.
(6) Connect 100-ohm thermistor mount (A8) to the TI.
(7) Set the TI MOUNT RES switch to 100.
(8) Repeat (2) through (5) above.
b. Adjustments
. On model 431C, adjust L1 (fig. 1)(L102, fig. 2 on model 431B) for
null on the TI.
Summary of Contents for 431B
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