Instruments for monitoring pH and/or Redox (ORP) in water.
Redox or ORP (Oxidation-Reduction Potential) measurement is used to indicate the presence of oxidizing or reducing conditions in water. In pure water treatment, ORP is generally used to assure the removal of chlorine or other oxidizing agent ahead of membranes or deionization resins that could be damaged by oxidation.
pH measurement in high purity water is challenging for various reasons. The low conductivity of pure water in combination with the vulnerability to contamination, the variability of reference electrodes and additional temperature effects converge to make this a particularly challenging measurement. Overcoming these obstacles requires a thorough understanding of the potential problems and their systematic solution.