HP E4418A, Service Manual

Page: 46 / 108

Performance Tests
Zero Test
2-6 HP EPM-441A/442A Service Guide
Procedure
The following procedure should be performed for the Zero Test.
Note The procedure details the key presses required on the
HP EPM-441A. For the HP EPM-442A the equivalent key presses
should be performed on both channels.
1. Connect the equipment as shown in Figure 2-1.
2. Switch the power meter on.
3. Press then .
4. Press , for a reading in watts.
5. Set the range calibrator as follows:
RANGE............................................ 3
µ
W
POLARITY ...................................... NORMAL
FUNCTION..................................... STANDBY
LINE................................................ ON
Note When switching the range calibrator to STANDBY, allow enough
time for the range calibrator to settle to its zero value before
attempting to zero the power meter. This settling would appear on
the power meter display as downward drift. When the drift has
reached minimum, (typically less than 60 seconds), the range
calibrator is settled.
6. On the power meter press , ,
select 512 from the pop up window then press .
7. On the power meter press , . When the wait symbol
disappears press . Wait approximately 10 seconds for the
wait symbol to disappear.
8. Wait 30 seconds then verify that the power meter’s reading is
within
±
0.05
µ
W. Record the reading.
Table 2-2: Zero Test Results
Min
Channel A
Actual Result
Channel B
Actual Result
(HP EPM-442A
Only)
Max
-76.40 nW ________________ ________________ +76.40 nW
Preset
Local
Confirm
dBm/W
W
System
Inputs
Input Settings Filter
Enter
Zero
Cal
Cal
Zero
4402serv.book Page 6 Monday, March 11, 2002 11:34 AM