Patent ID: 6071393
Filing Date: 2000-06-06
Classification: G01N

Abstract:
A sensor for measuring nitrogen oxide concentration, comprising:(a) different first, second and third solid electrolyte cells in a lamination;(b) an insulating layer being interposed between the first and second solid electrolyte cells; and(c) another insulating layer being interposed between the second and third solid electrolyte cells;wherein(d) a first cavity is provided with the first electrolyte cell as a first oxygen pumping cell and the second electrolyte cell as an oxygen concentration measuring cell, said first and second electrolyte cells each having a solid electrolyte layer and having a pair of porous electrodes, one of said electrodes of the first electrolyte cell facing said cavity;(e) a second cavity is provided with the third electrolyte cell as a second oxygen pumping cell having a solid electrolyte layer and a pair of porous electrodes;(f) a volume of the first cavity is more than two times the volume of the second cavity;(g) a diffusion path for diffusing the nitrogen oxide from the first cavity to the second cavity is formed penetrating through the second electrolyte cell;(h) one of said electrodes of the second electrolyte cell that measures oxygen concentration is located around an inlet of the diffusion path; and(i) the electrode of the first electrolyte cell facing the first cavity is extended along the solid electrolyte layer of the first cell in a direction toward but not reaching an area immediately above the inlet of the diffusion path.