Chlorine Sensors & Transmitters

Chlorine Sensors & Transmitters

Chlorine measurement systems combine dedicated sensors and transmitters to monitor residual disinfectants in real time. Depending on the disinfectant strategy and water matrix, these instruments measure free chlorine, total chlorine, chlorine dioxide, ozone, and free bromine to maintain effective disinfection while limiting excessive dosing.

Many disinfectant sensors use an amperometric, membrane-covered measuring cell. The disinfectant diffuses through the membrane and is reduced at the working electrode, generating a current proportional to concentration; for free chlorine, pH-dependent speciation is compensated by parallel pH measurement and transmitter correction to maintain accuracy across operating conditions.

Continuous residual monitoring improves control of dosing systems and stabilizes disinfection outcomes, particularly where contact time, temperature, and demand fluctuate. It also supports regulatory compliance and mitigates risks associated with over-application of oxidants, including downstream impacts on materials, processes, and discharge quality.

Applications span drinking-water treatment, process and reuse water, pools, and seawater systems. Chlorine dioxide is often applied where pH independence and reduced corrosivity are beneficial (such as cooling systems, wash water, and certain desalination pretreatment steps), while total chlorine is commonly used to assess residual disinfectant status in treated wastewater and reuse streams.

Design typically centers on correct disinfectant selection, appropriate flow assembly/sample presentation, and maintenance planning for membrane/electrolyte components. Modular measuring points and preassembled monitoring panels can reduce installation effort while still supporting multichannel or multiparameter architectures where disinfection control must be coordinated with pH and other water-quality variables.

Engineered Equipment Company, a leading supplier of specialized industrial equipment.