The constant voltage principle electrode is used to measure residual chlorine, chlorine dioxide, and ozone in water. The constant voltage measurement method is to maintain a stable potential at the electrode measurement end, and different measured components generate different current intensities at this potential. It consists of two platinum electrodes and a reference electrode to form a microcurrent measurement system. The residual chlorine, chlorine dioxide, and ozone in the water sample flowing through the measuring electrode will be consumed, so it is necessary to maintain continuous flow of the water sample through the measuring electrode during measurement.

The constant voltage measurement method uses a secondary instrument to continuously and dynamically control the potential between the measuring electrodes, eliminating the influence of the inherent resistance and redox potential of the measured water sample, and forming a good linear relationship between the electrode measurement current signal and the concentration of the measured water sample. It has very stable zero point performance, ensuring accurate and reliable measurement.