Method for determining filling level of aqueous urea solution in reducing agent tank of nitrogen oxide- reduction system of internal combustion engine of vehicle, involves obtaining level from temporal progression of temperature curve

摘要

The method involves heating a reducing agent (102) by selective actuation of a reducing agent heater (105). A temperature rise is detected over a predetermined time interval using temperature sensors (110). A filling level is obtained from the temporal progression of a temperature curve. A variable e.g. thermal loss and heat transfer resistance, between the temperature sensors is empirically determined by the reducing agent heater, where the variable influences the temperature rise. The variable is stored in a temperature characteristics diagram. Independent claims are also included for the following: (1) a computer program with a set of instructions for performing a method for determining a filling level of a reducing agent in a reducing agent tank of a nitrogen oxide- reduction system of an internal combustion engine (2) a computer program product with a set of instructions for performing the method for determining the filling level of the reducing agent in the reducing agent tank of the nitrogen oxide- reduction system of the internal combustion engine.