Patent ID: 7997065

Claim:
A device for estimating a loading state of a NO X storage catalytic converter, with the NO X storage catalytic converter storing nitrogen oxides which are contained in an exhaust gas of an internal combustion engine, the device comprising: a module for determining an oxygen concentration difference between an oxygen concentration present in the exhaust gas upstream of the NO X storage catalytic converter and an oxygen concentration present in the exhaust gas downstream of the NO X storage catalytic converter, the module comprising a first chamber provided in a section of an exhaust line that is upstream of the NO X storage catalytic converter having a first oxygen concentration; and a second chamber provided in a section of the exhaust line that is downstream of the NO X storage catalytic converter having a second oxygen concentration, the first chamber and the second chamber each being configured to reduce nitrogen oxide (NO X ) to form nitrogen and oxygen, and wherein the module is configured to determine an oxygen concentration difference between the first oxygen concentration and the second oxygen concentration; and a controller for estimating the loading state of the NO X storage catalytic converter based on the oxygen concentration difference, wherein the module for determining the oxygen concentration difference includes a Nernst cell provided between the section of the exhaust line that is upstream of the NO X storage catalytic converter and the section of the exhaust line that is downstream of the NO X storage catalytic converter, and wherein the Nernst cell includes a first end and a second end, the first end connected to the first chamber that is provided in the section of the exhaust line that is upstream of the NO X storage catalytic converter and the second end connected to the second chamber that is provided in the section of the exhaust line that is downstream of the NO X storage catalytic converter.