Chlorine Residual Analyzer – Online Water Disinfection Monitoring for SCADA The Chlorine Residual Analyzer is a critical online analytical instrument used in water and wastewater treatment plants to continuously measure free or total chlorine levels in treated water. Maintaining the correct chlorine residual is essential for effective disinfection, regulatory compliance, and ensuring safe drinking water delivery. This analyzer is integrated into SCADA automation systems, providing real-time measurements to PLCs or RTUs, which in turn relay the data to operator dashboards for monitoring, trend analysis, and automated process control.
The device typically includes a sample conditioning unit, flow cell, and sensor. It measures chlorine concentration using amperometric or colorimetric methods, converting chemical activity into an electrical signal proportional to the chlorine level. The output is then sent to SCADA systems via 4–20 mA analog signals or digital protocols like Modbus RTU, HART, or Ethernet, allowing seamless integration with plant control architecture. Continuous monitoring enables precise control of chlorine dosing pumps, helping optimize chemical use, reduce costs, and prevent over-chlorination, which can produce harmful disinfection by-products.
Chlorine analyzers are designed for robust operation in challenging environments, including highly chlorinated water, wastewater, and corrosive conditions. Many models feature automatic cleaning, calibration, and diagnostic capabilities to reduce maintenance and ensure accurate measurements over long periods. They can be installed at critical points such as post-disinfection tanks, distribution lines, or effluent discharge points to provide continuous assurance of water safety.
Hach CL17/CL19 Online Chlorine Analyzer Datasheet (PDF) https://www.hach.com/asset-get.download.jsa?id=7639988633