TB 9-4935-365-24
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 and/or technical
manuals for the TI.
d. Unless otherwise specified, all controls and control settings refer to the TI.
WARNING
A possible safety hazard exists with test instrument if a three-
to- two wire adapter is used, or if the instrument is powered
from the optional battery pack with line cord disconnected.
Safety problem is ac voltage potential between instrument case
and ground. INSURE THAT THE INSTRUMENT CASE IS
GROUNDED by connecting the ground lead between earth
ground and the hinge pin on instrument case, using a test lead.
NOTE
Values shown in parenthesis throughout this procedure pertain
to model 8120A.
7. Equipment Setup
WARNING
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 check where applicable.
a. Remove protective cover from TI only to make adjustments and replace upon completion.
b. Connect TI to a 115 V ac source.
c. Set POWER switch to ON and allow at least 30 minutes for equipment to warm-up
and stabilize.
d. Press function V DC and RANGE 1 (100 MV) pushbuttons. For model 8125A only,
press FLTR ON-OFF pushbutton to ON.
NOTE
Insure that ground strap is connected between INPUT LO and GD terminals.
e. Short INPUT HI and LO terminals. If TI does not indicate between +.0001 (+00.01)
and -.0001 (-00.01) adjust ZERO (fig. 1) (for model 8120A, adjust DC ZERO (front panel)
control to center range, and adjust ZERO (fig. 1) until TI indicates .0000 (00.00).
