FCL Series sensors use amperometric measurement technology to provide accurate monitoring of free chlorine in process applications. The sensors are compliant with U.S. EPA method 334.0 for measuring drinking water. Models are available to cover 0- to 2-ppm, 0- to 5-ppm and 0- to 10-ppm ranges. The sensors’ membrane design features a mesh reinforcement clamp for stability and durability. The integral 4-20 mA isolated signal output is enhanced to eliminate ground loop errors, reduce noise and block high-voltage transient surges.