GAS-ANALYSIS WITH ARRAYS OF SOLID-STATE ELECTROCHEMICAL SENSORS - IMPLICATIONS TO MONITOR HCS AND NOX IN EXHAUSTS

Solid-state electrochemical sensors based on stabilized zirconia may b e used for monitoring gas mixtures of several electro-active component s. Concepts of multi-component analysis with potentiometric and ampero metric sensors are discussed with respect to the simultaneous detectio n of O-2 and HCs or O-2 and NOx in exhausts. Recent results demonstrat e the possibilities of continuously detecting oxygen, HCs and NOx with arrays of potentiometric or arrays of amperometric electrodes. Ampero metric arrays are preferable because of the possibilities connected wi th fixing oxygen activities and reaction conditions by the applied pot entials. The results also demonstrate that system solutions have to be found for each application.