Non-sinusoidality of a signal as a source of error in instruments measuring root-mean-square value

摘要

This paper presents additional errors resulting from the finite frequency band transferred by converters of true root-mean-square value. These errors are revealed in a specific way on converting non-sinusoidal signals into dc voltage. Approximated expressions, which make it possible to calculate quickly the uncertainties for some typical signal waveforms, are given, enabling instrument users to evaluate the accuracy of the measurement performed. It is also shown that the precision of non-sinusoidal signal measurements depends primarily on the frequency bandwidth. The possibility is considered of using the derived expressions in systems with automatic correction of measurement results.