DIGITAL SAMPLING-TYPE MEASURING APPARATUS

PURPOSE:To obtain a measuring apparatus which can find the effective value or the mean-value rectification of repetitive waveforms up to a high frequency. CONSTITUTION:An apparatus is provided with a sample-and-hold circuit 30 which samples and holds the input signal of repetitive waveforms in synchronization with a sampling clock fs, with an A/D converter 40 which converts the output of the sample-andhold circuit 30 into a digital signal and with an operation device 70 which operates the output of the A/D converter 40. In the apparatus, a plurality of sampling clock generators 51, 52 which generate sampling clocks are installed, and one out of the plurality of sampling clock generators is selected and changed over in such a way that the frequency (f) of the input signal and the sampling clock fs do not have a relationship of f+(1/2).fs.n (where n=1, 2, 3,...) when a mark + is used as a symbol representing proportion.