Rapid-Response Semiconductor Sensor With Resistance Detection Determines Partial Pressure of Oxygen

In the past, solid electrolytes have mainly been used as oxygen sensors for automobiles. This type of sensor measures the difference between the oxygen partial pressures of a reference electrode and a measurement electrode, and always requires a reference electrode. Consequently, the problem with this type of sensor is that the sensor structure is complex, making miniaturization difficult. To resolve this problem, a resistance-type oxygen sensor has been developed that does not require a reference electrode. Also previously, resistive oxygen gas sensors have exhibited slow response times, making such a sensor difficult to incorporate into an effective feedback system, such as those used to control modern electronic fuel injection systems for gasoline engines.