| 摘要 |
PROBLEM TO BE SOLVED: To minimize an effect caused by a fraction occurring in the number of times of sampling due to a lag generated between a measuring period and a sampling period.SOLUTION: An effective value measuring method includes: a first step of measuring in advance, one period of a measurement target signal; and a second step of sampling in a predetermined sampling period, the measurement target signal over a period which is an integer multiple of one period measured in the first step, and calculating an effective value of the measurement target signal from the sampled measurement data. During one-period measurement in the first step, the measurement target signal is sampled in a predetermined sampling period over the one period, and a temporary effective value TVrms of the measurement target signal is calculated from the sampled measurement data, and then the temporary effective value TVrms is set to a starting point of the sampling in the second step.SELECTED DRAWING: Figure 2 |
