Patent ID: 6495027
Filing Date: 2002-12-17
Classification: G01N

Abstract:
A gas sensor for determining a concentration of gaseous components of a gas mixture having at least NOx in an exhaust gas of an internal combustion engine, the gas sensor comprising:a sensor body formed from a plurality of oxygen-ion-conducting solid electrolyte layers; a first measuring-gas compartment formed within said sensor body; a first pump cell comprising at least one inner pump electrode within said first measuring-gas compartment disposed on a solid electrolyte layer and at least one outer pump electrode disposed on an opposite side of said solid electrolyte layer, said first pump cell used for transporting oxygen one of into and out of said first measuring-gas compartment; a second measuring-gas compartment formed within said sensor body, wherein a gas mixture can flow directly from said first measuring-gas compartment into said second measuring-gas compartment; a second pump cell comprising at least one inner pump electrode within said second measuring-gas compartment disposed on a solid electrolyte layer and at least one outer pump electrode disposed on an opposite side of said solid electrolyte layer, said second pump cell used for transporting oxygen one of into and out of said second measuring-gas compartment; a third measuring-gas compartment formed within said sensor body, wherein a gas mixture can flow directly from said first measuring-gas compartment to said third measuring-gas compartment; and a third pump cell comprising at least one inner pump electrode within said third measuring-gas compartment disposed on a solid electrolyte layer and at least one outer pump electrode disposed on an opposite side of said solid electrolyte layer, wherein the at least one inner pump electrode is selected from a material that catalytically decomposes NOx into at least oxygen, said third pump cell used for transporting oxygen one of into and out of said third measuring-gas compartment; wherein said second pump cell and said third pump cell generate a measurable pump current corresponding to the oxygen concentration within their respective measuring-gas compartments.