TB 9-6625-1185-24
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
OUTPUTS to minimum after each step within the performance
check where applicable.
a. Remove protective cover from TI.
b. Mechanically adjust TI zero-adjust (INF) screw for 0 indication on VOLTS meter
and for ∞ (INFINITY) on MEGOHMS meter.
c. Connect TI to autotransformer.
d. Connect autotransformer to a 115 V ac source and adjust for 115 V output.
e. Turn DC ADJUST control fully ccw.
f. Set POWER switch to ON and allow at least 10 minutes to warm-up and stabilize.
g. Turn TI ZERO ADJ (∞ ADJ) control to midrange and MULTIPLIER switch to
ZERO ADJ (CHK).
h. On model 1620D, set TEST VOLTAGE MULTIPLIER switch to X1 position.
i. Press and hold TEST VOLTAGE switch and adjust internal ZERO ADJ (INF)
control (fig. 1) for INFINITY indication on MEGOHMS meter. Release TEST VOLTAGE
switch.
Figure 1. Megohmmeter - left view.