The MFC analyzer/controller offers an easy,software selectable range of control modes from flow proportional, residual control only, compound loop and set point trim enabling precise control of a chlorinator or metering pump to maintain the desired level of disinfection and water quality. Up to four water quality parameters, such as free and total chlorine, chlorine dioxide, ozone, fluoride, conductivity, redox, pH, and temperature can be measured by single or multiple cells. A variety of flow cells are available, including the proven Depolox® 5 , bare-electrode measuring cell for free chlorine, potassium permanganate, chlorine dioxide and ozone and the VariaSens™flow block for utilizing internally buffered oxidant sensors. This flexibility provides for an almost limitless combination of continuous measurement technologies for the same sample or different samples from the entire treatment process.