Many drinking water systems add fluoride to their water to help their residents prevent tooth decay. To achieve a fluoride concentration of about 1 PPM, a hydrofluorosilicic acid or sodium fluoride solution is metered into the process at a rate that is proportional to total plant flow. However, flow control problems may result in a loss of chemical feed or over-feed condition. An on-line fluoride monitor can provide reliable control of chemical addition for a consistent fluoride concentration.

ATI’s Model Q46F/D Fluoride Monitor provides continuous measurement of free fluoride concentration in potable water without sample conditioning. The system employs a fluoride sensitive ion selective electrode (ISE) which provides reliable measurements down to 0.1 PPM and as high as 1000 PPM. The system is designed for use in applications where the pH and conductivity of the water are relatively stable. Fluoride measurement applications with widely varying sample conditions may require a more sophisticated system employing automated sample conditioning such as ATI’s Q46F-AutoChem system.

Fluoride monitoring systems are easy to install, requiring a ¼” O.D. sample tube connected to a special flowcell provided as part of the system. Inlet flow must be regulated to 6 GPH (0.4 LPM) or less and should be stable. As an option, ATI can supply the fluoride monitoring system factory mounted on a panel containing all necessary flow controls and a visual flow indicator.