Gas sensor element using porously fired mass of titania

Abstract

The invention relates to a gas sensor element which utilizes a change in the electric resistance of a porously fired TiO.sub.2 layer. To improve the speed of response of the gas sensor element, and also to strengthen the adhesion of the fired TiO.sub.2 layer to a ceramic substrate, at least one kind of metal oxide which hardly undergoes solid phase reaction with TiO.sub.2 and serves as a sintering suppressing agent, such as Er.sub.2 O.sub.3, Sm.sub.2 O.sub.3 and/or In.sub.2 O.sub.3, is added to TiO.sub.2 in advance of firing. The speed of response is further enhanced by the addition of at least one kind of noble metal such as Pt and/or Rh to TiO.sub.2 together with the sintering suppressing oxide(s).

Dependencies are inferred from the claim text.