HIGH-SENSITIVITY OXYGEN SENSOR BASED ON PHASE TRANSITION FOR PROPORTIONAL CONTROL AND METHOD FOR DETECTING OXYGEN PARTIAL PRESSURE CHANGE WITH USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a sensor showing superior sensitivity and reaction time at various air-fuel ratios. ;SOLUTION: A method and a sensor for detecting a change in oxygen partial pressure in an ambience through a change of a measurable physical property of a detection substance are provided. The sensor 10 includes a detection substance 12 selected from a metal or metallic oxide which can change between a phase A where the metal or metallic oxide is present and a different phase B when the sensor is exposed at high temperatures to a gas including oxygen changing its partial pressure. In accordance with a phase change, the measurable physical property of the substance changes. Since it is important that the detection substance is present at least at two phases during an active detection operation, the sensor 10 also includes a heating means 19 which maintains a temperature gradient traversing the detection substance and is connectable to a power source. An output signal is generated in accordance with the change of the physical property such as an electric resistance or the like of a part or the whole of the detection substance corresponding to the change of the oxygen partial pressure.;COPYRIGHT: (C)1999,JPO