AWWA WQTC71340

This study evaluated the accuracy of amperometric technology for measuring chlorine residual concentrations in practical applications relative to the reference colorimetric method. The authors analyzed responses of several colorimetric and amperometric analyzers to changes introduced to the same sample. The comparison was conducted anonymously, the sample conditions were tightly controlled, and the tests included, but were not limited to, the following parameters: response time; LOD/LOQ; short-term and long-term repeatability; and, pH and conductivity dependence. The study was conducted according to the guidelines of the ISO method for process analyzers evaluation (ISO 15839:2003). In the course of presenting the study results and discussion, the authors made several observations indicating that performance specifications of online amperometric analyzers are often overstated by the manufacturers. The main conclusion of the study was that, in general, colorimetric systems performed better compared to amperometric/polarographic systems. Includes 6 references, tables, figures.