Method for detecting portion of e.g. oxygen, in exhaust gas tract of internal combustion engine, involves detecting concentration of gas species in measuring gas area from signal staying in relation with change of gas species concentration

摘要

The method involves adjusting or regulating a voltage between electrodes (128, 150) of an electrochemical cell (152) from outside in such a manner that a defined concentration of a gas species is adjusted in an inner chamber (116) using electrochemical pumps. The voltage is modified in such a manner that the concentration or the amount of gas species to be detected is changed in the inner chamber. The concentration of the gas species in a measuring gas area (112) is detected from a signal that stays in relation with the change of concentration of the gas species.