In-line detector system for real-time determination of impurity concentration in a flowing gas stream
Patent 5325705 Issued on July 5, 1994. Estimated Expiration Date: 
August 17, 2012. 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.
August 17, 2012. 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 ReferencesOxygen analyzer Method and device for processing measured values Method of detecting and or removing trace amounts of condensible vapors from compressed gas In-line detector system for real-time determination of impurity concentration in a flowing gas stream Patent #: 5138869 InventorAssigneeApplicationNo. 930184 filed on 08/17/1992US Classes:73/31.03, Impurity73/23.2, GAS ANALYSIS422/83Means for analyzing gas sampleExaminersPrimary: Warden, Robert J.Assistant: Dawson, E. Leigh Attorney, Agent or FirmInternational ClassG01N 029/02AbstractAn in-line detector system for real-time detection of impurity concentration in a flowing gas stream. In a specific aspect, the system may comprise a purifier unit for selective purification of gas from the gas stream, and an impurity addition unit for imparting a predetermined concentration of impurity to the gas stream, whereby the resulting concentration sensings of the purified gas, and the impurity-enhanced gas are usefully employed to calibrate an impurity concentration sensor, for continuous accurate sensing of impurity concentration in the flowing gas stream. The system may utilize hygrometric sensors in the case of water as a critical impurity, or surface acoustical wave (SAW) devices coated with suitable impurity-affinity coatings. The system has particular utility in monitoring low impurity concentration levels (e.g., from about 0.1 ppm to about 100 ppm) in gas streams employed in vapor-phase processes such as chemical vapor deposition in the manufacture of semiconductor devices.Other References
| |
