Meter Mechanical Zero; Battery Operation - HP 432A Manual

Model 432A
1. Connect thermistor
THERMISTOR MOUNT connector. Refer to
Table 1−2 for recommended thermistor mounts
and their frequency ranges.
2.

Meter Mechanical Zero:

a. With the instrument turned off, rotate the
meter adjustment screw clockwise until the
pointer approaches the zero mark from the
left.
b. Continue the clockwise rotation until the
pointer coincides with the zero mark. If the
pointer overshoots, continue rotating the
adjustment screw clockwise until the
pointer once again approaches the zero
mark from the left.
c. Rotate the adjustment screw about three
degrees counterclockwise
screw adjustment
suspension.
3. Set the MOUNT RES switch to correspond to
the operating resistance of thermistor mount
used.
4. Turn the 432A POWER switch ON. For battery
operation, the AC LINE indicator does not turn
on.
mount and cable
to disengage
from the meter
NOTE: The photograph opposite is for
illustration purposes only.
Figure 3−4. Turn On and Zeroing Procedure (Sheet 2 of 2)
to 5. Set RANGE selector to COURSE ZERO and
then zero the meter with the COURSE ZERO
screwdriver adjustment.
The power meter should be zeroed with the
RF power source turned off, or the mount
disconnected from the source.
6. Set the range selector to the 0.01 mW range;
then depress the FINE ZERO switch until the
meter indicates zero.
Range-to-range zero carryover is less than
±0.5% if the meter zero has been adjusted
(step 2 above), and the instrument has been
properly zero-set on the sensitive range. For
maximum accuracy, zero-set the power
meter on the range to be used.
7. Set CALIB FACTOR switch to correspond to
Calibration Factor imprinted on HP thermistor
mount label.
8. Apply RF power to the thermistor mount. Power
is indicated on the meter directly in mW or dBm.
Section III
Operating Information
Note
Note
3−9