Patent ID: 8601795

Claim:
A process for detecting at least one of an amount of reducing agent and an amount of pollutant in an exhaust gas, the process comprising the acts of: emitting a first measuring signal proportional to the amount of the reducing agent and to the amount of the pollutant in the exhaust gas; filtering the exhaust gas by reducing one of the reducing agent and the pollutant in the exhaust gas; emitting a second measuring signal proportional to the amount of the reducing agent and to the amount of pollutant in the filtered exhaust gas; determining at least one of the amount of the reducing agent and the amount of the pollutant in the exhaust gas based on a difference between the first and second measuring signals; and increasing a dosing amount of the reducing agent when the determined amount of pollutant increases and lowering the dosing amount of the reducing agent when the determined amount of reducing agent increases.