| 摘要 |
PROBLEM TO BE SOLVED: To provide an RMS-measuring device for adjusting zero point by directly measuring the output offset eo(rms) of an RMStoDC converter without using any reference voltages. SOLUTION: The RMS-measuring device is provided with a first switch circuit for selectively outputting an input signal and a zero-potential signal, a variable DC signal generator for generating an arbitrary DC signal, an adder for outputting the addition signal of the output of the first switch circuit and that of the variable DC signal generator, a preamplifier for inputting the output of the adder, an RMStoDC converter for inputting the output of the preamplifier and then outputting a signal corresponding to the RMS value of the input signal, a second switch circuit for selectively outputting the output of the preamplifier and that of the RMStoDC converter, a measurement circuit that is connected to the output of the second switch circuit, and at least a control circuit for controlling the first switch circuit, the second switch circuit, and the variable DC signal generator.
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