Multilayered air-fuel ratio sensing element

摘要

A multilayered air-fuel ratio sensing element comprises a solid electrolytic substrate having oxygen ion conductivity. A measuring gas sensing electrode is provided on one surface of the solid electrolytic substrate so as to be exposed to a measuring gas. A reference gas sensing electrode is provided on another surface of the solid electrolytic substrate so that the reference gas sensing electrode is exposed to a reference gas introduced into a reference gas chamber. The measuring gas sensing electrode is covered by a porous diffusive resistor layer. And, a hollow space is provided between the measuring gas sensing electrode and the porous diffusive resistor layer.