Importance

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Abstract

Errors introduced into ac waveform measurements based on discrete amplitude samples because the waveform period is not an integral number of sampling intervals are substantially averaged out by computing the aggregate average of the set averages of sets of samples. Each set is taken over approximately an integral number of waveform cycles, and the set terminations are spread uniformly over approximately an integral number of cycles. Each set may overlap the previous set by all but one sample. As a short cut to the computation, each sample of the first set may be weighted with a weighting factor that is a respective member of an arithmetic series, starting at one and increasing in steps of one. Each remaining sample may be weighted by a factor that is a member of symmetrical series decreasing in steps of one and ending in one. The sum of all the weighted samples is accumulated and divided by the sum of all the weighting factors to produce the average of averages, or dc value of the waveform. The rms value can be produced by squaring the samples before weighting and taking the square root of the average of averages.

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First Claim