Element for detecting an air/fuel ratio

摘要

The present invention discloses an element for detecting an air/fuel ratio which avoids dispersion in the detection accuracy, caused by the nonuniformity of the direction along which the element is fastened on an exhaust pipe. In the case of the element, an annular solid electrolyte layer having conductivity in response to oxygen ions is integrated on a heater section which is designed in the form of an elongated bar. The inner and outer electrodes are arranged on an inner or outer surface, respectively, of the solid electrolyte layer. A protective layer is integrally formed in the shape of a ring, in order to protect the solid electrolyte layer and the outer electrode.