A calculable, transportable audio-frequency AC reference standard

Abstract

A transportable ac voltage source is described, in which sinusoidal signals are digitally-synthesized in the audio-frequency range. The rms value of the output waveform may be calculated by measuring the dc level of the individual steps used to generate the waveform. The uncertainty of this calculation is typically 10 ppm from 20 Hz - 10 kHz at the 7 V level.