In the production process of ion exchange membrane alkali production, calcium, magnesium ions, and other metal ions in saltwater have a significant destructive effect on the ion exchange membrane. The service life and economic indicators of the ion exchange membrane in the electrolytic cell are closely related to the quality of the secondary brine. In order to ensure the excellent performance of the ion exchange membrane, it is necessary to control the content of impurity ions such as Ca² and Mg² in the brine entering the cell very low, so as to meet the requirements of the ion exchange membrane alkali production process for brine quality.

Coarse salt water is filtered through a membrane to produce refined salt water. The control of impurity ions such as Ca² and Mg² in the refined salt water directly affects the service life of the resin tower. The use of a calcium magnesium online analyzer can monitor the Ca² and Mg² content of the refined salt water, the membrane filtration effect, and the alkalinity of the crude salt water in real time. Thus achieving the purpose of monitoring and guiding production.