Measuring component concentration in a gas blend
Patent 4902138 Issued on February 20, 1990. Estimated Expiration Date: 
April 4, 2008. 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.
April 4, 2008. 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 References 3444739 3607084 3616677 Temperature sensor and detector cell utilizing the same Thermal conductivity detector Patent #: 4594879 InventorsAssigneeApplicationNo. 176888 filed on 04/04/1988US Classes:374/44, Thermal conductivity73/25.03, Thermoconductivity73/204.25, Resistive element338/22RThermistor typeExaminersPrimary: Yasich, Daniel M.Attorney, Agent or FirmForeign Patent References
International ClassesG01N 031/00G01N 025/18 Foreign Application Priority Data1987-04-04 DEAbstractThe thermal conductivity in a gas blend is measured in order to determine concentration using several different temperatures for the gas but the same sensor, which includes a Silicon carrier of a few hundred micrometers thick and being provided with an electrically insulating layer; carrying a sputtered on or vapor deposited, meandershaped thin film resistance; a pit in the carrier underneath the resistance and the insulating layer, there being one or more perforations in the insulation to permit access of gas to the interior of the pit; a cover plate made also of silicon and of comparable thickness dimensions as the carrier, and also having a pit of comparable dimensions as the first mentioned pit is disposed above the carrier so that said pits are aligned and constitute a common measuring chamber; and a diffusion channel in the cover plate for feeding a gas through diffusion so that the measuring chamber is defined by the communicating pits. | |
