TB 9-6625-2364-24
(4) Connect digital multimeter (resistance mode) between VRF terminal center
conductor on power meter (rear panel) and pin 1 of thermistor mount end of power meter
interconnect cable.
(5) Round off digital multimeter indication to two decimal places and record this
value as power meter internal bridge resistance R (value will be approximately 200 Ω).
(6) Connect thermistor mount to power meter interconnect cable.
(8) Press Preset Local, [Confirm] keys.
(9) Set power meter RANGE switch to COARSE ZERO and adjust front panel
COARSE ZERO control for a zero meter indication.
(10) Fine zero power meter on most sensitive range then set power meter RANGE
switch to 1 mW.
(11) Ensure multimeter input terminals are isolated from chassis ground for (12)
below.
(12) Adjust multimeter (dc mode) controls to measure microvolts.
(13) If multimeter indication is 400 V or less, record digital multimeter indication
and proceed to (15) below; if not, proceed to (14) below.
(14) Hold power meter FINE ZERO CONTROL and adjust COARSE ZERO control
for a multimeter indication 200 V or less. Record multimeter indication.
(15) Round off indications recorded in (13) or (14) above to two decimal places and
record this value as V0.
(16) Set power meter to highest range.
(17) Disconnect multimeter negative lead from power meter VRF (fig. 3) and connect
multimeter negative lead to power meter chassis ground.
(18) Press TI Zero Cal, [Cal], More, [Power Ref On] keys.
(19) Round off indications to two decimal places and record this value as VCOMP.
(20) Reconnect multimeter negative lead to power meter VRF input.
(21) The multimeter is now set up to measure V1.
(22) Calculate the required value of V1 using the following formula:
V1 = VCOMP + V0 - √VCOMP2 - (10)-3 (4R)(Calibration Factor)
(23) Adjust A2R90 (fig. 4) until multimeter indicates value calculated in (22) above.
a. Deenergize and disconnect all equipment.
b. Annotate and affix DA label/form in accordance with TB 750-25.