The seawater backflow monitoring project of Chongming County Water Conservancy Project Management Office.

The project is of great significance as it concerns the water safety of the entire residents and crops on Chongming Island. Previously, without automatic monitoring of whether seawater was backflowing, seawater often entered Chongming Island, affecting the growth of crops and resulting in low crop yields. It has increased the cost of water quality treatment in the early stage of waterworks.
Under such circumstances, the Chongming Water Conservancy Bureau proposed to promptly control the entry of seawater into the island. This project was highly challenging as each gate was far from the monitoring room, making remote control difficult. Through the knowledge I had acquired, I realized that the most significant difference between seawater and fresh water lies in their varying salt content. Therefore, I adopted a salinity analyzer to control the seawater.
When choosing electrodes, another problem was encountered. The traditional PT100 temperature compensation is greatly affected by distance, which will affect the accuracy of the data. I resolutely adopted a 30K thermistor as the salinity and temperature compensation. It was not affected from 50 meters to 100 meters, accurately monitoring the high and low tides of the seawater. This project is of great significance and has benefited the entire Chongming Ecological Island.