LIMITING-CURRENT CHLORINE GAS SENSOR BASED ON BETA''-ALUMINA SOLID ELECTROLYTE

A new type of limiting-current solid-state ionic gas sensor for gases that may not be transferred in solid electrolytes is presented. The sensor is based on the reaction of the gaseous species with the electroactive component under the condition of limited access of the gas by a kinetic barrier. The technique allows the presently available fast solid alkali metal, silver and copper ion conductors to be used at ambient and moderately increased temperatures. A linear relationship between the electrical current and the gas concentration is observed for chlorine gas. The device may be operated at lower temperatures than the potentiometric chlorine gas sensor, is sensitive to low partial gas pressures and may also overcome problems of cross-sensitivity. Sensors for gases other than chlorine may be based on the same principle.