C Measurement Uncertainty Analysis - Power Reference Level Test
154 Keysight E4416A/E4417A Power Meters Service Guide
The reference is designed to have a VSWR of less than 1.05.
VSWR < 1.05
Hence,
So u(M
s
) from the equation above equals:
Mismatch Uncertainty U(M
s
) worst case:
Calibration factor
The calibration factors supplied with the power sensor take into account the
performance of the sensor with respect to frequency. This value is of secondary
importance when calculating the overall uncertainty of the 1 mW reference.
The information that is appropriate is the Uncertainty of the Calibration Factor.
The power sensor must be calibrated such that:
Uncertainty of Calibration Factor < 0.2%
Therefore,
U(CF) = 0.002
P
s
max()P
d
max()
VSWR 1–
VSWR 1+
--------------------
1.05 1–
1.05 1+
--------------- 0.0244== ==
uM
s
()
0.0244()0.0244()×
2
---------------------- -----------------
± 0.00042==
UM
s
2P
s
P
d
22 uM
s
()× 0.0012== =
To Next Page
Loading...
Need help?
General
