What is Chlorine Dioxide (CLD)?

Chlorine dioxide is a neutral chlorine compound. It is very different from elementary chlorine, both in its chemical structure (ClO2) and in its behavior. One of the most important qualities of chlorine dioxide is its high water solubility, especially in cold water. Chlorine dioxide does not hydrolyze when it enters water; it remains a dissolved gas in solution. Chlorine dioxide is approximately 10 times more soluble in water than chlorine. It is not affected by pH and has an excellent residual effect remaining active for hours to days. It does not interact with ammonia or ammonium. It is effective in cold temperatures.

Chlorine Dioxide Sensors & Accessories

  • water flow regulator
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  • Free Chlorine Flow Cell
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  • chlorine dioxide maintenance kit
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  • chlorine dioxide sensor
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How is Chlorine Dioxide Measured?

An amperometric sensor design consists of two electrodes (anode and cathode), a membrane and fill solution. These sensors measure a change in current caused by the chemical reduction at the cathode. A membrane and electrolyte help to control the reaction. Constant flow rate and pressure are controlled to ensure an accurate measurement.

ORP can also be used with relatively clean water and Chlorine Dioxide concentrations less than 3ppm. While it doesn’t specifically measure chlorine, it responds to all oxidation reduction reactions present and is indicative of free sanitizer available.

Why is Chlorine Dioxide Measurement Necessary?

Chlorine dioxide is one of the most effective disinfection methods measurements in the water industry today. These measurements ensure effective use of chlorine dioxide for disinfection purposes as well as other applications. Under dosage can be ineffective and over dosage results in excess Chlorite by product formation. It is extremely effective in controlling legionella.

Common Applications:

  • Pre-oxidant for drinking water safety
  • Fruit and other foods washing and disinfection
  • Sanitizing production lines
  • Disinfecting medical equipment
  • Bleaching of wood pulp
  • Cooling tower disinfection
  • Bottle washing


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