Residual Chlorine Monitoring
Pi has three residual chlorine analysers for free and total chlorine. These are the HaloSense based on the electrochemical technology, the DPDSense (an online DPD analyser) and the ChloriBrid (hybrid, innovative and patented XXXXX. Both technologies that bring the benefits of both to a single Chlorine analyser.
Residual chlorine analysers from Pi are used in many applications requiring the measurement and control of online residual chlorine levels in water. The range is suitable for total or free residual chlorine monitoring or control applications in potable water, seawater, process water, swimming pool water, wastewater, food washing, paper and pulp, etc.
The Pi range of controllers/transmitters means that you get exactly what you need and nothing that you don’t. From a low cost no-frills chlorine dosing controller (CRONOS®) to a highly sophisticated colour display, remote access controller (CRIUS®4.0) – and all with the same great sensors! Chlorine dosing control is now simpler and cheaper than ever! Both controllers can have multiple sensors and multiple sensor types, saving money on the requirement for one sensor and one transmitter per measurement.
Online electrochemical is an online DPD method of measuring residual choline has different strengths and weaknesses, so depending on your application you maybe better off with an electrochemical solution (HaloSense) or online DPD solution (DPDSense) or if you need the benefits of both the hybrid ChloriBrid will be the instrument of choice for you.
When chlorine is added as a disinfectant to water it oxidises material in the water thereby killing any organisms. The ‘Residual Chlorine’ is the chlorine left over at the end of the process and is usually what we measure.
Free chlorine is the chlorine in the water that exists as HOCl or OCl–. When chlorine is added to pure water between pH 4 and pH 11
Cl2 + OH– ↔ HOCl + Cl–
HOCl ↔ OCl– + H+
so if chlorine is added to water you get HOCl (Hypochlorous acid) and OCl– (Hypochlorite), which together make ‘free chlorine’.
If water contains both ammonia and hypochlorite it will react to form monochloramine.
NH3 + OCl– → NH2Cl + OH–
In an acidic solution Monochloramine disproportionates to form Nitrogen Trichloride.
2NH2Cl + H+ → NHCl2 + NH4+
3NHCl2 + H+ → 2NCl3 + NH4+
In solution where there are low concentrations of chlorine it is often Chloramines that can be smelled not ‘chlorine’. The three Chloramines above are collectively known as ‘Combined Chlorine’.
No. Total Chlorine is the sum of Free Chlorine and Combined Chlorine, therefore Total Chlorine is always equal to or greater than both Combined Chlorine or Free Chlorine.
Click on any of the buttons below to see of product details
"The support from Pi and its partners is superb. They go above and beyond to ensure that, not only is their equipment perfect but that the process is working great too. Five Stars!"
Equip Solutions - Illinois, USA
Everyone at Pi goes out of their way to be supportive and timely. Their expertise is unchallenged and I am very happy to endorse them as a quality supplier.
Chemtrac - Georgia, USA
Servicing customers is much more than just solving problems or addressing complaints and Pi does that very competently with technical and quick efforts providing a good experience.
Buckman - Latin America