Correction device of air-fuel ratio detection apparatus

Abstract

According to the present invention, there is provided: a sensor element including an oxygen concentration detection section consisting of solid electrolyte for outputting a detection signal corresponding to an oxygen concentration in a hollow chamber to which an exhaust of an internal combustion engine is introduced and an oxygen pump section for controlling an electric current to be applied to a solid electrolyte wall that divides the hollow chamber from an exhaust side of the engine so that the oxygen concentration in the hollow chamber becomes a predetermined oxygen concentration, to flow oxygen into/out of the hollow chamber; an air-fuel ratio detection circuit for outputting an air-fuel ratio detection value based on the electric current applied to the solid electrolyte wall by the oxygen pump section; and a pump current cut off circuit for cutting off the power supply to the solid electrolyte wall by the oxygen pump section, and a detection value of air-fuel ratio is corrected based on an output value of the air-fuel ratio detection circuit of when the power supply to the solid electrolyte wall by the oxygen pump section is cut off by the pump current cut off circuit, while detecting the air-fuel ratio over a wide range.