Patent ID: 9395325
Filing Date: 2016-07-19
CPC Classification: G01N

Claim Text:
1. A gas sensor to be exposed to gas to be measured, comprising a sensor element having a closed-bottomed tubular solid electrolyte body having a closed forward end and extending in a direction of an axis, an outer electrode portion provided on an outer surface of a forward end portion of the solid electrolyte body, and an outer lead portion extending rearward from the outer electrode portion in the direction of the axis and having a circumferential width narrower than a width of a rear end region of the outer electrode portion; and a heater having a heat-generating portion formed of a heat-generating resistor which generates heat through application of electricity, and being in contact with an inner surface of the sensor element, the gas sensor being characterized in that the outer electrode portion has at least an outer partial electrode portion formed partially with respect to a circumferential direction of the outer surface, and the outer electrode portion is disposed at such a position as to face a contact portion of the inner surface of the sensor element in contact with the heater with the solid electrolyte body intervening therebetween, and a surface area S of the outer electrode portion is 8% to 20% of a surface area T of a gas contact portion of the solid electrolyte body to be exposed to the gas to be measured.