| 摘要 |
An oxygen sensor element (1) has: a solid electrolyte body (2) having oxygen ion conductivity; a measurement electrode (3) having catalytic action, the measurement electrode (3) being provided to one surface of the solid electrolyte body (2); a reference electrode (35) having catalytic action, the reference electrode (35) being provided to the other surface of the solid electrolyte body (2); and a heater (5) for heating the measurement electrode (3). When oxygen concentration in a measurement gas (G) is measured by the oxygen sensor element (1), in the measurement electrode (3) heated by the heater (5), the ratio (%) of the surface area (S1) of a low-temperature region having a surface temperature less than 450°C of the surface area (S) of a contact site exposed to the measurement gas (G) is 15% or less. |
