A calculable, transportable audio-frequency AC reference standard

A transportable AC voltage source is described in which sinusoidal signals are synthesized digitally in the audio-frequency range. The root-mean-square (r.m.s.) 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 at the 7-V level is typically less than +or-5 p.p.m. from 60 kHz and less than +or-10 p.p.m. from 30 Hz to 15 kHz.<
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