N191xA Power Meter
Range Accuracy Verification test
20dBm (100mW)
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Table of Contents
1. Overview .............................................................................................................................................................. 3
2. Instrument Accuracy Test......................................................................................................................................... 4
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1. Overview

This document describes the condition during range accuracy verification using the 11683A Range
Calibrator especially at 20dbm (100mW).
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2. Instrument Accuracy Test
Equipment
Range Calibrator
Power Sensor Cable
Agilent 11683A
Agilent 11730A
Test Setup
Figure 1-1 Instrument Accuracy Test Setup
Procedure
The following procedure should be performed for the Instrument Accuracy Test.
1. Connect the equipment as shown in Figure 1-1.
2. Switch on the power meter.
3. Press Preset, then confirm.
4. Press DISP  units  W for readings in Watt.
5. Press Disp  Resolution to set the resolution to 4.
6. Set the range calibrator as follows:
RANGE
3µw
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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 will appear on the power meter display as
downward drift. When the drift reaches minimum (typically less than 60 seconds), the range calibrator is
settled.
7. On the power meter, press Channel  set Measure Averaging to Manual  set to 512 and then
press enter.
8. On the power meter, press Cal, Zero. Wait approximately 10 seconds for the wait symbol to
disappear. Verify that the display reads 0±0.05µW.
9. Set the range calibrator’s FUNCTION switch to CALIBRATE.
10. Set the range calibrator’s RANGE switch to 1mW.
11. Press Cal to calibrate the power meter.
12. Set the range calibrator’s RANGE switch to 100mW.
Figure 1-2 Default display when the Range Calibrator is connected to the N1912A
Observation:
1. The default display setting for the N1912A at the upper window is Single Numeric.
Therefore, you will not be able to see the “over range” message on the screen since
there is no scale indication.
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Figure 1-3 Default display when the Range Calibrator is connected to the N1911A
Observation:
1. The default display setting for the N1911A is Single Numeric at the upper window and
Analog display at the bottom window. Therefore, you will see an “over range” message at
the analog view.
2. The pre-set scale on Analog display is set at min -70dBm (100pW) and max 20dBm
(100mW) and the display will show “over range” when tested at 20dBm. This is normal
because the reading already exceeds the maximum limit but is still within the range. As
long as the measurement is still within the spec limit, “over range” is not an issue and the
unit is good. You can change the maximum limit by changing the scale:
Press DISP  1 of 2  Anlg Mtr Scaling  Enter the desired max limit.
Figure 1-4
3. Alternatively, you can either select the Single or Dual numeric display to view the readings
without bothering with the max and min scale.
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Figure 1-5 Dual Numeric Display – without scale
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