The online chloride ion sensor adopts a highly stable solid-state membrane ion selective electrode, designed specifically for real-time monitoring of chloride ion concentration in water quality. The measurement range covers 0~3500 mg/L or 0~35000 mg/L, with an accuracy of ± 5% of the reading and fast response (T90<60s). Built in Pt1000 automatic temperature compensation ensures accurate data. Supports RS-485 (Modbus RTU) and optional 4-20mA output, making it easy to connect to systems such as PLC and DCS. IP68 protection level, corrosion-resistant POM/316L shell, 3/4 "NPT thread, can be submerged or installed in pipelines. The electrode has a long lifespan, simple calibration, and is suitable for industrial wastewater, surface water, and other scenarios.