Electro-Chemical Devices” TCA-22 AnalyzerSystem features built-in pH compensation in a virtual plumb-and-play design. The total chlorine analyzer is designed for use in drinking water,industrial cooling and rinse water, wastewater or other fresh water samplescontaining chlorine in the range of 0-20 PPM. It is a good fit for applicationsin municipal water systems and a range of water-based processes in thechemical, electronics, electric power, food/beverage, oil/gas, pharmaceutical,pulp/paper and other industries. The unit’stotal chlorine amperometric sensor features a built-in pH sensor thatautomatically compensates for samples with a four to 12 pH concentration.This capability eliminates the need for sample conditioning systemswith consumable reagents to control the pH level in the solution. Theamperometric sensor is a three-electrode design, which measures all chlorinespecies in the water, combined chlorine and free chlorine. The sensor isconstructed with one gold cathode, one silver halide anode and a 304 stainlesssteel counter electrode. The counter electrode provides a stable basepotential that minimizes drift for high accuracy. The sensor’s micro-porous membrane allows ions to diffuse in and out of thesensor. The various chlorine species in the measured sample diffuse intothe sensor and react with the acidic potassium iodide electrolyte to formiodine. The iodine is reduced at the cathode back to iodide and the currentflow between the cathode and silver iodide anode is proportional to totalchlorine. While amperometric chlorine sensors are flow sensitive, the TCA-22 features aconstant head flow control device (ECD) design. It maintains the optimumflow by the sensor over a range of incoming sample flowrates from 38 to300 L/hr (10 to 80 gal/hr). It operates over a wide temperature rangefrom 0 C to 45 C (32 F to 113 F). A built-in analyzer allows either total chlorine or pH tobe displayed graphically.  User-defined ranges allow easy trend analysisof either parameter. The panel-mount design of the sensor comes pre-wired and with assembledflow tubing. Advanced sensor and controller technologies allowinstallation and commissioning to be completed in just three steps. All that is necessary is to connect the sampleand drain lines, connect the power and outputs. Calibration is accomplished by DPD comparison.