CL4.2MA2 Free Chlorine Sensor

Applied in Residual Chlorine Monitoring of Water Treatment Plants

A municipal water treatment plant adopts a sodium hypochlorite disinfection process, requiring real-time monitoring of residual chlorine concentration in finished water (water leaving the plant) and end-of-pipeline water to ensure drinking water safety. Previously, the monitoring equipment used by the plant suffered from insufficient accuracy in low-concentration residual chlorine detection and frequent data deviations when water temperature or pH fluctuated—posing hidden risks to water quality control. These issues were effectively resolved after the introduction of the DCL4.2MA2.

Residual Chlorine Monitoring for Finished Water
The DCL4.2MA2 covers a measurement range of 0.005~2.000ppm with a resolution of 0.001ppm, enabling precise capture of residual chlorine changes in finished water (where concentrations exceed 0.3mg/L). Even when residual chlorine approaches the upper limit of 2mg/L, it maintains stable measurement accuracy. Additionally, it is compatible with a pH range of 6~8, which highly matches the plant’s actual tap water pH environment (6.5~7.8), eliminating interference from pH fluctuations on residual chlorine detection.

Residual Chlorine Monitoring for End-of-Pipeline Water
To meet the requirement that residual chlorine in end-of-pipeline water must remain above 0.05mg/L, the DCL4.2MA2 demonstrates excellent low-concentration detection capability. It can accurately capture slight fluctuations in end-of-pipeline residual chlorine within the 0.05~0.1mg/L range, preventing "missed detection of compliance" or "false alarm of exceeding limits" caused by equipment misjudgment. Furthermore, the device features automatic temperature compensation, maintaining stable data without manual calibration even when the plant’s water temperature fluctuates between 5~30℃ during daily operations.

Operational Performance & Maintenance
The DCL4.2MA2 has a response time of approximately 30 seconds. In case of abnormal residual chlorine spikes or drops due to disinfection system malfunctions, it triggers alarms quickly—securing valuable intervention time for the plant. Its housing is made of PVC-U and ABS materials, paired with an IP68-protected 5-pin M12 aviation connector, ensuring stable operation in the plant’s humid environment without short-circuit risks. Meanwhile, the membrane cap has a 1-year replacement cycle, and the electrolyte is replaced every 3~6 months—greatly reducing maintenance frequency and avoiding monitoring interruptions caused by equipment shutdowns for repairs.

Application Effects
Since its deployment, the continuity and accuracy of residual chlorine data for the plant’s finished water and end-of-pipeline water have significantly improved, providing a reliable basis for water quality compliance. It has also reduced labor and time costs associated with equipment maintenance, becoming a key component of the plant’s water quality monitoring system.