| 摘要 |
PROBLEM TO BE SOLVED: To secure a measurement accuracy to satisfy a requirement for practical use, at least, in frequently required measurement subsections and also to enable the measurement over a wide range. SOLUTION: By connecting a sensor 3 for a characteristic value measurement with an variable-gain amplifier 5 and control circuit 7, setting the control circuit 7 on one or more threshold values correspondingly to the measurement subsections over the whole measuring range, making the control circuit 7 form a control signal when an output of the sensor 3 exceeds the threshold value, setting the gain of the amplifier 5 to be more than two-stepped by the control signal, and thus, the measurement accuracy of the characteristic values can be changed over more than two-stepped. |
