Method for operating exhaust gas sensor e.g. nitrogen oxide-sensor in internal combustion engine in motor vehicle for maintaining legal defined emission boundary value, involves setting value for determining impedance of sensor cells

摘要

The method involves scanning sensor signals (Sense) in a time discrete manner, where the signals comprise a Nernst-voltage signal (GS) and alternating voltage signal (WS). Scanning values are processed to separate the alternating voltage signal of known frequency from the Nernst-voltage signal. Magnitude of the Nernst-voltage signal represents a value for regulating oxygen concentration in exhaust gas of an internal combustion engine. Another value that represents amplitude of the alternating voltage signals is set for determining impedance of sensor cells i.e. Nernst-cells. An independent claim is also included for a device for operating an exhaust gas sensor in an internal combustion engine.