Development of titania heated exhaust-gas oxygen sensor

In this system, the composition of the engine exhaust gas must be maintained in a narrow range around the stoichiometry point to achieve high conversion efficiency for the catalyst. The closed-loop feedback control system using an oxygen sensor has been developed for this purpose. Two types of oxygen sensors have been developed: the potentiometric type using zirconia (ZrO/sub 2/) ceramic electrolyte and the resistive type using titania (TiO/sub 2/) semiconductor ceramics. A new electrically heated sensor has been developed which is inexpensive and tolerates lead. This sensor is installed with a multilayered substrate, using thick-film titania and a special interface design.