DEVICE FOR MEASURING OXYGEN CONTENT IN GAS MEDIUM

PROBLEM TO BE SOLVED: To determine an air-fuel ratio in an internal-combustion engine from the composition of exhaust fumes or, in particular, from the partial pressure of oxygen remaining in the exhaust fumes. SOLUTION: The invention concerns a device including: a sensor capable of supplying a representative voltage representative of the ratio between a reference oxygen pressure and the pressure of oxygen in the volume of the sensor, which is provided with electrodes (12, 14) capable of passing therethrough a pumping current controlling the pressure of oxygen in the volume; and controlling/commanding means including a digital controller (26) suitable to receiving the representative voltage on an input and supplying the pumping current. The controlling/commanding means supplies the pumping current in the form of a continuous, gradual and non-chopped current, and is controlled by the digital controller so as to automatically set the input voltage at a predetermined value. COPYRIGHT: (C)2009,JPO&INPIT