Oxygen-sensing system
Patent 4519237 Issued on May 28, 1985. Estimated Expiration Date: 
October 26, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
October 26, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesMixture control monitor apparatus Method and apparatus for measuring the O2 content of a gas Gas sensor Air-fuel ratio detecting system Air-fuel ratio control method and apparatus utilizing an exhaust gas concentration sensor Patent #: 4462374 InventorAssigneeApplicationNo. 06/545696 filed on 10/26/1983US Classes:73/23.21, With compensation detail (for error or drift correction, etc.)123/693, With compensator for sensor output (e.g., current or voltage)73/25.03ThermoconductivityExaminersPrimary: Kreitman, Stephen A.Attorney, Agent or FirmInternational ClassG01N 27/12 (20060101)Foreign Application Priority Data1982-10-30 JPAbstractA sensing element exposed to a gas to be analyzed has an internal resistance which depends on its temperature and also on the oxygen concentration in the gas. A thermistor has an internal resistance which depends on its temperature. The thermistor is positioned near the sensing element so that the temperature of the thermistor substantially coincides with the temperature of the sensing element. The ratio of the internal resistances of the thermistor and the sensing element is substantially independent of the temperature of the thermistor and the sensing element but is dependent on the oxygen concentration in the gas. A first device serves to sense the internal resistance of the thermistor and thereby determine the temperature of the sensing element. A second device serves to sense the ratio of the internal resistances of the thermistor and the sensing element and thereby determine the oxygen concentration in the gas. At first, the first device is enabled and the second device is disabled. When the determined temperature of the sensing element rises to a predetermined reference level, the first device is disabled and the second device is enabled. | |
