Easing the Problem of Traceability for Complex Waveforms by Optimizing Instrument Design

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Easing the Problem of Traceability for Complex Waveforms by Optimizing Instrument Design (267.28 Ko)

Instruments providing previously unavailable facilities often pose challenges for those responsible for providing measurement traceability. The main challenge in the case discussed in this paper was to measure the phase of up to eight channels of complex voltage and current waveforms with five to ten times better accuracy than available from commercially available systems. The resulting solution had to be cost effective for third party calibration facilities and those who maintain their own traceability. As is often the case, a simple solution turned out to be extremely effective but the implementation would not have been possible without early collaboration between metrology and instrument design functions. The paper describes how novel instrument system design allowed phase and amplitude of various harmonically distorted and amplitude-modulated waveforms to be determined with a single digitising DMM and a few voltage dividers and shunts. Other potential measurement system architectures are reviewed and system traceability issues are discussed.