| 摘要 |
PROBLEM TO BE SOLVED: To make rapidly reducible an erroneous measurement caused by a polarization effect in a sensor by inverting the shape of a current between a reference electtrode and measurement electrode into a pulse shape just after the completion of each pumping current pulse. SOLUTION: A sensor voltage US lowering through a sensor SO is measured through an RC filter, composed of a resistance R2 and a capacitor C, and a switch S3, with the switch S3 closed. With a switch S1 closed, a pumping reference current is periodically supplied in a pulse shape to the sensor SO via a resistance R1. A power source G of opposite direction is insertionwise provided to be connected parallely to the sensor SO through the switch S2. Just after the switch S1 is opened, the switch S2 is operated to apply an inverted current pulse to the sensor SO just after a pumping current pulse is supplied. Thereby, the polarization effect caused by the pumping current is made reducible. |
