Patent ID: 10663424

Abstract:
A sensor element includes a laminate, in which a plurality of oxygen ion-conductive solid electrolyte layers are stacked and in which a measurement object-gas flow portion is disposed, an inside pump electrode disposed on the inner circumferential surface of the measurement object-gas flow portion, an auxiliary pump electrode, and a measurement electrode. Then, the value of the volume ratio (Va=Vm/Vr) is 14.5 or more and 51.5 or less and the value of the volume ratio (Vb=Vs/Vr) is 5.0 or more and 17.5 or less, where the volume of the inside pump electrode 22 is specified as (Vm), the volume of the auxiliary pump electrode 51 is specified as (Vs), and the volume of the measurement electrode 44 is specified as (Vr).