Measurement Uncertainty Analysis – Power Reference Level Test
Measurement Introduction
Measurement Introduction
In the Power Reference Level Test, the output from the DUT’s 1mW Power Ref connector is measured.
A 432A Power Meter and an 8478B H01 Power Sensor are required for this test. Also the H01 power sensor’s calibration factor uncertainty at 50MHz must be no greater than ±0.2%.
A 3458A DMM is required to read the Vref and Vcomp outputs of the 432A. This is preferred to estimating an inaccurate visual reading from the 432A front panel.
Define the Measurand
The measurand is the output power of the 1mW reference in the DUT.
Define the Measurement Equation
Pmeas = | 2 ⋅ Vcomp ⋅ | (V1 – V0) + V02 – V12 |
⋅ |
where,
V0 is the voltage measured between Vcomp and Vref with no power applied, for example, the reference switched off and after the 432A has been zeroed.
V1 is the voltage measured between Vcomp and Vref with power applied, for example, the reference switched on.
Vcomp is the voltage between the 432A Vcomp rear connector and chassis ground with power applied.
R is mount resistance of the 432A meter.
CF is the value of the Calibration Factor of the Thermistor mount at 50MHz.
Ms is the mismatch magnitude between the DUT reference and the 8478B sensor, which is equal to:
Ms = 2 ⋅ Ps ⋅ Pd
Agilent E4416A/E4417A Service Guide |
