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W137 — Establishing traceability for a high-performance ac/dc transfer standard

Introduction of new, high-accuracy alternating voltage DMMs and calibrators in the past few years has presented the electronics test equipment industry with the challenge of supporting their accuracy. A group at Fluke was tasked with developing an ac/dc transfer standard having uncertainties of about ± 10 ppm at moderate levels and frequencies, an accuracy that results in a ratio of product specification to National Institute of Standards and Technology (NIST) uncertainty of about 2:1. A major challenge was to develop and communicate a credible calibration system to support this product. Rigorous application of statistical principles to successive intercomparisons of nearly identical artifacts
had already been proven capable of maintaining a Direct Voltage Standard within a few parts in 100 million of the 10 volt standard maintained at NIST, a ratio of about 1.2:1. This note describes the system developed to support traceable calibration of this new ac/dc transfer standard through application
of these proven statistical techniques.