Chlorine analyser eliminates pH sampling systems and reagents

Paul Boughton
Electro-Chemical Devices's Model TCA-22 is a Total Chlorine Analyzer, which is designed for use in drinking water, industrial cooling and rinse water, wastewater or other fresh water samples containing chlorine in the range of 0-20 ppm. 

It is suitable for application in municipal water systems and a wide range of water-based processes in the chemical, electronics, electric power, food/beverage, oil/gas, pharmaceutical, pulp/paper and many other industries.

The TCA-22’s advanced total chlorine amperometric sensor features a built-in pH sensor that automatically compensates for samples with a 4 to 12 pH concentration.  This capability eliminates the need for expensive sample conditioning systems with consumable reagents to control the pH level in the solution.  There’s also no maintenance labor required to monitor and replace the reagents.

The TCA-22’s amperometric sensor is a three electrode design, which measures all chlorine species in the water, combined chlorine and free chlorine.  The sensor is constructed with one gold cathode, one silver halide anode and a 304 stainless steel counter electrode.  The counter electrode provides a stable base potential that minimises drift for high accuracy.

The TCA-22 sensor’s micro-porous membrane allows ions to diffuse in and out of the sensor.  The various chlorine species in the measured sample diffuse into the sensor and react with the acidic potassium iodide electrolyte to form iodine.  The iodine is reduced at the cathode back to iodide and the current flow between the cathode and silver iodide anode is proportional to total chlorine.

While amperometric chlorine sensors are flow sensitive, the TCA-22 features a constant head flow control device (ECD) design.  It maintains the optimum flow by the sensor over a wide range of incoming sample flow rates from 38 to 300 L/hr (10 to 80 gal/hr).  It operates over a wide temperature range from 0 to 45ºC (32 to 113ºF).

The TCA-22’s built-in C22 Analyzer allows either total chlorine or pH to be displayed graphically.  User defined ranges allow easy trend analysis of either parameter.  The C22 features a 2.5-x-1.75 inch LED display for local monitoring with simple menu’s and membrane switches for easy use.

The panel mount design of the TCA-22 comes pre-wired and with assembled flow tubing.  ECD's advanced sensor and controller technologies allow installation and commissioning to be completed in just three easy steps utilizing simple tools.  All that is necessary is to connect the sample and drain lines, connect the power and outputs and the TCA-22 is ready to use.  Calibration is accomplished by DPD comparison.

For more information, visit www.ecdi.com

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