Calibration Factor - Keysight Technologies E4417A Service Manual

C Measurement Uncertainty Analysis - Power Reference Level Test
The reference is designed to have a VSWR of less than 1.05.
VSWR < 1.05
Hence,
P s max
So u(M
u M s
Mismatch Uncertainty U(M
UM s

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
154
= P d max
( ) (
) from the equation above equals:
s
( 0.0244 )
( ) = ± - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
= 2P s P d = 2 2 u M s
VSWR 1
–
= - - - - - - - - - - - - - - - - - - - - =
)
VSWR 1 +
× ( 0.0244 )
= 0.00042
2
) worst case:
s
= 0.0012
× ( )
Keysight E4416A/E4417A Power Meters Service Guide
1.05 1
–
- - - - - - - - - - - - - - - = 0.0244
1.05 1 +