METHOD AND DEVICE FOR MONITORING THE OIL GAS MEASURING CAPABILITY OF AN EXHAUST GAS PROBE

摘要

The present invention relates to a method for monitoring the oil gas measurement capability of an exhaust gas probe in an exhaust gas duct of an internal combustion engine driven in a lean combustion mode, wherein the exhaust gas is exhausted from the exhaust gas duct through a diffusion barrier. It diffuses into the measurement cavity of the gas probe, and by applying a pump voltage between the electrodes through a pump cell having an internal pump electrode and a second pump electrode, oxygen is pumped into or out of the measurement cavity corresponding to the flow pump current. In this case, during the lean combustion mode of the internal combustion engine, in the diagnosis step, the pumping direction of the pump cell is reversed so that oxygen is pumped into the measurement cavity, and the oil gas measurement capability of the exhaust gas probe is inferred from the pump current and/or the pump voltage. Further, the invention relates to an apparatus for the execution of the method of the present invention. The method and apparatus of the present application makes it possible to perform a diagnosis of the oil gas measurement capability of an exhaust gas probe without converting the exhaust gas composition of the internal combustion engine to a rich exhaust gas. Accordingly, an increase in fuel consumption or emission of the internal combustion engine can be prevented.