A method for monitoring a mass of soot in a particulate filter

A method for monitoring a mass of soot in a particulate filter (14) of an exhaust system (12), comprising: Predicting a soot mass (46) in the particulate filter (14) based at least in part on a pressure difference (42) between the filter (14) flowing exhaust gas (20) and from the filter (14) flowing exhaust gas (20); marked by Checking the predicted soot mass (46) based at least partially indicate on measured operating parameters, including a mass flow (32) of nitrogen oxides in the exhaust gas flow (20) of the exhaust system (12) and a temperature (38) of the particulate filter (14) wherein the checking comprises: Estimating a deviation between the predicted soot mass (46) and the actual mass of soot in said filter (14) by applying the measured operating parameters (32, 38) and the predicted soot mass (46) to a stored database (62, 66) of deviations (48 ) between predicted soot mass (46) and actual soot mass, which are measured over a plurality of respective Rusbeladungszyklen at least one particulate filter, which is substantially identical (to the particulate filter 14), each deviation (48) (in the stored database 62, 66) average for a respective modeled filter temperature and a respective average measured mass flow rate of nitrogen oxides in a respective one of Rusbeladungszyklen stands.