| 摘要 |
PROBLEM TO BE SOLVED: To provide an oxygen sensor element capable of suppressing the discharged amount of NOx to a low level in an internal combustion engine having the oxygen sensor element adopted.SOLUTION: An oxygen sensor element 1 has: a solid electrolyte 2 having oxygen ion conductivity; a measurement electrode 3 provided on one surface of the solid electrolyte 2 and having catalytic action; a reference electrode 35 provided on the other surface of the solid electrolyte 2 and having catalytic action; and a heater 5 for heating the measurement electrode 3. In an area S of a contact portion, exposed to a gas G to be measured, of the measurement electrode 3 that is heated by the heater 5 when an oxygen concentration in the gas G to be measured is measured by the oxygen sensor element 1, a ratio (%) of an area S1 of a low-temperature region in which the surface temperature is lower than 450°C is 15% or less. |
