Chlorine Sensors & Transmitters

Chlorine Sensors & Transmitters

Chlorine measurement systems provide continuous monitoring of disinfectant residuals in water and aqueous process streams. The category typically covers free chlorine, total chlorine (free plus combined), and related oxidants where selective measurement is required. A sensor paired with a transmitter converts electrochemical reaction signals into stable, temperature-compensated process values for control and compliance.

The key benefit is consistent disinfection performance with minimized chemical overfeed. Stable residual control supports pathogen inactivation targets while reducing taste/odor issues, byproduct formation, and chemical cost. Continuous monitoring also provides rapid detection of residual loss due to process upsets, high demand events, or dosing system faults.

Common measurement principles include amperometric sensors with membrane-covered electrodes and defined electrolyte systems, designed for fast response and robust selectivity. Depending on the residual type, measurement may incorporate pH compensation or be paired with a pH signal to correct for hypochlorous acid/hypochlorite equilibrium. Proper flow conditions - often provided by a flow assembly - improve repeatability and help protect the sensor from air entrainment and debris.

Transmitters provide scaling, filtering, diagnostics, and communications for integration into control architectures. Advanced diagnostics (sensor impedance, polarization status, slope monitoring) help distinguish true residual changes from sensor drift or fouling. Cleaning strategies range from manual wipe-down to automated flushing, with maintenance intervals driven largely by water quality, solids loading, and biofouling tendency.

Typical applications include drinking water treatment and distribution, disinfection contact basins, wastewater disinfection, industrial cooling water, and sanitization processes in food and beverage utilities. Residual monitoring is also used to verify dechlorination performance before discharge and to protect downstream biological treatment stages. With correct installation and verification practices, chlorine measurement becomes a dependable lever for both safety and cost control.

Instrumentation and Controls., an exclusive authorized representative of sales and service for Endress+Hauser.