C Measurement Uncertainty Analysis - Power Reference Level Test
C-138 E4416A/E4417A Power Meters Service Guide
So the total power incident or measured by the Agilent 432 Power meter is 
given by:
The equation above includes the worst- case mismatch magnitude 2P
s
P
d
 and is 
in the form where various powers can be multiplied by the equation to find 
worst- case power levels with respect to mismatch.
In all cases P
d
 is extremely small therefore P
d
²
 terms tend to zero leaving.
M
s
Unc erta inty 112P
s
P
d
±()⁄=
From the above mismatch uncertainty equation if Pd is zero, for example, the 8478B 
sensor is exactly 50 ohms then there is NO mismatch uncertainty. This has not yet been 
achieved but efforts will be made in the future to try to achieve as near as possible to a 
'zero' level of mismatch uncertainty and hence have negligible mismatch when 
calibrating products.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com