TB 9-6625-2189-24
c. Unless otherwise specified, verify the results 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 manufacturer's manual for this TI.
d. Unless otherwise specified, all controls and control settings refer to the TI.
7. Equipment Setup
HIGH VOLTAGE is used or exposed during the performance of
this calibration.
DEATH ON CONTACT may result if
personnel fail to observe safety precautions.
REDUCE
OUTPUT(S) to minimum after each step within the
performance checks where applicable.
a. Connect TI to a 115 V ac power source.
b. Ensure INPUTS FRONT/REAR switch is in the FRONT (out) position.
NOTE
When TI is turned on, an internal self-test is performed. TI
inputs must be left open-circuited while the self-test is
performed otherwise the TI may indicate errors are present.
Errors may also be caused by inductive or capacitive pick-up
from long test leads. If option 09 is not installed in model
8840A the TI skips tests 1, 2, and 3.
c. Press TI POWER switch to ON and allow at least 1 hour for warm-up and
stabilization.
d. Press and hold TI SRQ pushbutton for 3 seconds. The TEST annunciator will then
light up and TI will run through its analog test in sequence. Each test number is displayed
for approximately 1 second.
e. If TI detects an error during one of the tests, it displays the ERROR annunciator
and the test number for approximately 2 1/2 seconds and then proceeds to the next test.
f. If TI fails to perform diagnostic self-test, perform paragraph 14 below.
8. Dc Volts
a. Performance Check
(1) Connect a high quality short between TI HI and LO INPUT terminals.
(2) Press TI V DC function pushbutton.
(3) Press TI RATE pushbutton for a SLOW (S) reading rate on display.
(4) Press TI 200 /mV range pushbutton.