| 摘要 |
PROBLEM TO BE SOLVED: To detect NOx concentration with high accuracy with a simple structure by forming an NOx detecting cell with the oxygen ion conductive first solid electrolyte body, an NOx active electrode on the measured gas side facing a gas diffusion resistive layer, and a facing electrode provided on the opposite face. SOLUTION: This NOx sensor element 1 is constituted of a gas diffusion resistive layer 13 for a measured gas guide path stacked on an NOx detecting cell 11 and an oxygen pumping cell 12 stacked on it and having an oxygen discharging function. The NOx detecting cell 11 is constituted of a facing electrode provided on the surface of the oxygen ion conductive first solid electrolyte body 110 and an NOx active electrode 111 on the measured gas side facing the gas diffusion resistive layer 13. The gas diffusion resistive layer 13 of the NOx sensor element 1 rate-controls the diffusion of gas. When the oxygen concentration in the atmospheric gas is changed, for example, the diffusion of oxygen molecules is rate-controlled in response to each concentration, and the sensor output becomes proportional to the oxygen concentration. |
