Patent ID: 11933757
Assignee: DENSO CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A NOx sensor comprising:
a housing;
an insulator retained by an inner periphery of the housing;
a sensing device which includes a solid electrolyte body which is disposed in the insulator and has oxygen ion conductivity, a front end portion of the sensing device in a lengthwise direction of the NOx sensor protruding from a front end surface of the insulator; and
a protective cover which is secured to a front end portion of the housing so as to cover the front end portion of the sensing device and has formed therein cover inlet holes which direct a measurement gas to the front end portion of the sensing device, wherein
a pump electrode and a sensor electrode are disposed in a front end portion of the solid electrolyte body in the lengthwise direction of the NOx sensor, the pump electrode being exposed to the measurement gas and regulating a concentration of oxygen in the measurement gas, the sensor electrode being exposed to the measurement gas and measuring a concentration of a given gas component in the measurement gas after being regulated in the concentration of oxygen by the pump electrode, and the given gas component whose concentration is measured by the sensor electrode is NOx,
a whole of the sensor electrode is located closer to a base end side of the NOx sensor than all the cover inlet holes formed in an outer periphery of the protective cover are in the lengthwise direction of the NOx sensor,
a base end of the sensor electrode in the lengthwise direction of the NOx sensor is located closer to the base end side of the NOx sensor than a front end surface of the housing is, and
at least a portion of the pump electrode is arranged outside of the housing, and the at least the portion of the pump electrode is located inside the protective cover.