Giga-tronics 58542 - Procedure

Calibration & Testing
Publication 21555, Rev. E, September 2002 4-3
4.3.1.2 Procedure
In the following steps, precision power measurements will be made using the HP432A Power Meter.
Refer to the HP432A manual for detailed operating information.
1. Connect the HP 432A to the Calibrator Output on the power meter as shown in Figure4-1.
2. Turn on all equipment and wait 30 minutes for the thermistor mount to stabilize before proceeding
to the next step.
3. Set the 432A Range switch to COARSE ZERO, and adjust the front panel COARSE ZERO
control to obtain a zero (
±2%FS) meter indication.
4. Set the DVM to a range that results in a resolution of 1
µV. Connect the positive lead to the
V
COMP
connector, and the negative lead to V
RF
connector, both on the rear panel of the HP 432A.
5. Fine zero the HP432A on the most sensitive range, then set the HP432A range switch to 1mW.
6. Record the DVM indication as V
0.
7. Turn on the power meter Calibrator RF power by sending
OUTP:ROSC ON
8. Record the reading shown on the DVM as V
1
.
9. Disconnect the DVM negative lead from V
RF
on the HP 432A and connect it to the 432A chassis
ground. Record the new DVM indication as V
COMP
.
10. Send
OUTP:ROSC OFF to turn off REFPOWER.
11. Calculate the Calibrator Output level (P
CAL
) using the following formula:
NOTE: Ensure that the DVM input leads are isolated from chassis ground when
performing the next step.
NOTE: The V
1
reading must be taken within 15 seconds after entering the command.
Otherwise, turn off REFPOWER as shown in Step9 and repeat Steps6 and 7.
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