Agilent Technologies E4418B, Руководство по обслуживанию

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Measurement Uncertainty Analysis – Instrument Accuracy Test
Measurement Introduction
A-4 Agilent E4416A/E4417A Service Guide
The Measurement Uncertainty is not calculated from different sensor and power
meter combinations, rather it is taken care of in the Customer Limit specification
setting. Hence using the same power meter and making measurements a number of
times will give us the uncertainty of the test station, without the uncertainty
associated with the meter itself. By taking n samples of the same meter/DUT in effect
we are averaging out the error associated with the DUT’s measurement capability
leaving us with a raw test station uncertainty which is made up from TSE and the
DMM error, for example, the Measured Voltage (MV).
The method that is used to calculate the Measurement Uncertainty of our test station
is a combination of Type A and Type B analysis in line with the ISO Expression of
Measurement Uncertainty Guide.
Uncertainty Equation
TSE
The Measurement Uncertainty of the Measurement Accuracy is calculated from
testing the same DUT at 5dB step power level from –25dBm to +20dBm.
Hence: Measurement Accuracy = f(MV , TSE)
u
2
MA
( )
C
TSE
u TSE
( ) ⋅ [ ]
2
C
M V
u MV
( ) ⋅ [ ]
2
+ =
4402serv.book Page 4 Tuesday, October 14, 2003 3:18 PM