Keysight Technologies N8480 Series, Operating And Service Manual

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Service 3
N8480 Series Power Sensors Operating and Service Guide 51
Zero Set Performance Test
This performance test is carried out to verify that a minimal amount of
residual offset error is present after zeroing has been performed. The
offset error is caused by contamination from several sources including the
noise of the device- under- test (DUT) itself. Zero set is the difference
between the power levels indicated by the DUT, after executing zeroing
and the true zero power. Ideally, this difference should be zero.
This performance test requires a compatible Keysight power meter with
the DUT and a computer with the Keysight IO Libraries Suite installed.
System specification:
±
25 nW, tested at 50 MHz
Recommended power meter: N1913A, N1914A
Recommended 50 MHz, 50
Ω
load: 85138B
Procedure
1 Connect the DUT (N8480 Series) to the power meter (N1913A) as
shown in the following diagram. Then, launch the Keysight IO Libraries
Suite on the computer.
2 Warm up the DUT for approximately an hour.
3 Launch the Interactive IO on the Keysight IO Libraries Suite to send
SCPI commands to the DUT.
4 Connect the DUT to the power meter 1 mW calibrator and perform
zeroing for the DUT by sending “
CAL:ZERO:AUTO ONCE
”.
5 Perform calibration for the DUT by sending “
CAL:AUTO ONCE
”.
6 Set the frequency of the DUT to 50 MHz by sending “
FREQ 50MHz
”.
7 Enable auto- averaging for the DUT by sending “
AVER:COUN:AUTO ON
”.
8 Change the power measurement unit of the DUT to watt by sending
“
UNIT:POW W
”.
DUT