FCL Series free chlorine sensors use amperometric measurement technology to provide accurate monitoring of free chlorine in process applications. The sensors are ideal for use in drinking water disinfection and distribution applications, and also are suited for free chlorine monitoring in cooling tower water. With three models available covering the 0- to 2-ppm, 0- to 5-ppm and 0- to 10-ppm ranges, the series meets a range of performance requirements.