Specifications

Measurement Uncertainty Analysis – Power Reference Level Test
Measurement Introduction
Agilent E4416A/E4417A Service Guide B-7
So u(Ms) from the equation above equals:
Mismatch Uncertainty U(Ms) 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 1mW reference.
The information that is appropriate is the Uncertainty of the Calibration Factor. The
power sensor must be calibrated such that:
Therefore,
Sensor Calibration Factor Drift
The Agilent Standards Laboratory at South Queensferry has determined the following
average sensor drift value.
Therefore
Note This value is only valid for 8478B sensors calibrated to 0.2% accuracy.
uMs()
0.0244()0.0244()×
2
----------------------------------------------------
± 0.00042==
UM
s
2P
s
P
d
22 uMs()× 0.0012== =
Uncertainty of Calibration Factor < 0.2%
UCF()0.002=
Average Sensor Drift < 0.06% per year
UDrift()0.0006=
4402serv.book Page 7 Tuesday, October 14, 2003 3:18 PM