Sensitivity Coefficients Ci; Combined Standard Uncertainty Uc(Y) - Keysight Technologies E4417A Service Manual

D Measuremet Uncertainty Analysis - Instrument Accuracy Test

Sensitivity Coefficients Ci:

The partial derivatives of the measurement equation
Y = f(MV, TSE) equal 1.
TSE is derived from a number of readings taken by the test station to characterize
the cabling, connectors noise and so forth. Therefore no measurement equation
exists to differentiate. It is a measured value of magnitude.
Hence:
C TSE
The DMM Measured Voltage also has a sensitivity coefficient equal to 1. As with
the TSE the Measured Voltage is not computed from an equation. Is it a real value
that the DMM actually measures.
Hence:
C MV

Combined Standard Uncertainty uc(y):

There is no correlation associated with this measurement
Hence:
uc
Table D-3
μW (
170
d
= - - - - - - - - - -TSE =
dTSE
d
= - - - - - - - - -MV = 1
dMV
2
∑
y ( ) = [ C TSE u TSE
shows the combined standard uncertainty at all the power levels from 3
25 dBm) to 100 mW (20 dBm).
−
1
2
⋅
( ) ] , [ C MV u MV
Keysight E4416A/E4417A Power Meters Service Guide
2
⋅
( ) ]