Gas sensor especially air/fuel ratio sensor for an automobile engine

摘要

Current supply to a heater (64), used to heat a solid electrolyte sensor element (60) of a gas sensor (30), is controlled according to the temperature increase rate. A gas component concentration measuring unit comprises a sensor (30) with a solid electrolyte sensor element (60) heated by an electric heater (64), the current supply of which is controlled by a heater control unit in accordance with the temperature rise rate of the sensor element (60). Independent claims are also included for the following: (i) a similar unit in which the current supply to the heater (64) is compensated according to the duration between the cold state and the activated state of the sensor (30); (ii) a similar unit for an engine, in which a voltage is applied to a resistance dominant region of the sensor on fuel interruption in order to determine the internal resistance of the sensor from the resulting current, the current supply to the heater being compensated according to this internal resistance; and (iii) a similar unit for an engine, in which current supply to the heater is compensated in dependence on the heater current supply quantity during a constant state of the engine and a predetermined standard value of the heater current supply quantity.