Agilent Technologies E4418B, Service Manual

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Measurement Uncertainty Analysis – Instrument Accuracy Test
Measurement Introduction
Agilent E4416A/E4417A Service Guide A-7
Worst case error on 15.8V maximum power setting
The relationship between the applied voltage from the Universal Source to the
corresponding power is given from:
1mW = 0.14493mV
This is a linear relationship, for example, 0.1mW is equal to 0.014493volts. This
relationship is valid between 0dBm and –30dBm.
However, above 0dBm a look up table is used for voltage to mW conversion. This is
due to the sensors non linear behavior at higher power levels. The voltage correction
at the appropriate points is shown in Table A-2.
Therefore to attain a power of 100mW as shown in the Table A-2, instead of applying
14.4493 Volts, the actual amount of voltage required from the Universal Source
would be:
14.4493 x 1.075533 = 15.6Volts
Voltage Error Distribution Standard Uncertainty
257.75uV Rectangular 148.8uV
Table A-2: Voltage Correction Multiplier
Power (mW) Voltage Correction Multiplier
1 1
10 1.006577
100 1.075533
Error = ((10ppm x 15.8V) + (0.3ppm x 100.0V)) + (0.5ppm x 15.8V) + 5((0.15ppm x 15.8V) + (0.1ppm x 100V))
= 257.75uV
Percentage Error = 0.00163%
4402serv.book Page 7 Tuesday, October 14, 2003 3:18 PM