OXYGEN SENSOR-BASED ON THE PRINCIPLE OF ELECTROCHEMICAL PUMP

A high-temperature oxygen sensor of limiting current with a porous lay er on the cathode to limit the diffusion rate of oxygen is investigate d arid fabricated. The solid electrolyte is made of Yttria-doped stabi lized zirconia (YSZ) and the porous platinum film electrode is deposit ed on the surface of YSZ. The relation between temperature arid oxygen concentration is tested at 629-degrees - 780-degrees-C in a mixture o f N2 and O2 with the oxygen concentration being 0 - 37%. Experimental results show a linear output with the oxygen concentration. The temper ature-dependence of its output can be explained by taking into account a mixed diffusion control mechanism of the ordinary and Knudsen diffu sion. The operating principle, structure arid performance of the senso r are discussed.