Measurement Uncertainty Analysis – Instrument Accuracy Test

Measurement Introduction

Measurement Introduction

In the Instrument Accuracy test the DUT measures power levels output from the test station from –25dBm to +20dBm.

A modified 8482A sensor is used to perform this measurement; it has had its thermocouple sensor (RF to DC converter) removed. This allows extremely accurate DC levels to be injected into the sensor from a 3245 Universal Source. The output from the universal source is measured at the head of the sensor by a 3458 DMM. In effect there is now zero measurement uncertainty associated with the Universal Source, as the 3458 DMM has assumed all the uncertainty.

In this test, DC signals are injected into the modified sensor. These are made in 5dB steps, from –25dBm to +20dBm. A conversion from voltage to power is required to achieve this. The measurement setup is shown in Figure A-1.

Figure A-1: Measurement Setup

Power Meter

T-Piece to measure DC

 

Drive Accurately

DUT

8482

Universal Source

DVM

A-2

Agilent E4416A/E4417A Service Guide

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Agilent Technologies e4418b, e4419b manual Measurement Introduction, Figure A-1 Measurement Setup