发明授权
US4018241A Method and inlet control system for controlling a gas flow sample to an
evacuated chamber
失效
用于将气体流动样品控制到抽真空室的方法和入口控制系统
- 专利标题: Method and inlet control system for controlling a gas flow sample to an evacuated chamber
- 专利标题(中): 用于将气体流动样品控制到抽真空室的方法和入口控制系统
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申请号: US619441申请日: 1975-10-03
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公开(公告)号: US4018241A公开(公告)日: 1977-04-19
- 发明人: Ingvar E. Sodal , Lars Hoivik , Alexander J. Micco , John V. Weil , Norman W. Baer
- 申请人: Ingvar E. Sodal , Lars Hoivik , Alexander J. Micco , John V. Weil , Norman W. Baer
- 申请人地址: CO Boulder
- 专利权人: The Regents of the University of Colorado
- 当前专利权人: The Regents of the University of Colorado
- 当前专利权人地址: CO Boulder
- 主分类号: H01J49/04
- IPC分类号: H01J49/04 ; H01J49/14 ; F16K31/02
摘要:
A method and inlet control system for controlling a gas flow sample to an evacuated chamber such as found in a mass spectrometer, is disclosed. The system utilizes a short inlet passage having an effective opening determined by a tapered diamond or steel tip needle adjacent to the inlet passage. The needle is positionally adjusted with respect to the inlet passage by being mounted on a piezoelectric crystal which is flexed by coupling thereto an electric potential derived by sensing the ions at the ionization chamber of a mass spectrometer, for example, and developing therefrom an electric signal indicative of the total pressure within the ionization chamber. The signal coupled to the piezoelectric crystal is preferably a pulse-width modulated signal with the needle maintaining the inlet passage closed except during the time that the piezoelectric crystal is flexed due to a received pulse. A vacuum pump, and a quadrupole filter, both of which are relatively small, are also disclosed, so that a mass spectrometer system, for example, is sufficiently compact so as to be useful, in conjunction with a respiratory valve, for the analysis of respiratory gases. The method for controlling a gas sample flow to a mass spectrometer, for example, comprises providing an inlet for a gas sample into the ionization chamber of the mass spectrometer, monitoring the pressure within the ionization chamber and developing an electrical signal indicative thereof, and utilizing the developed electrical signal to control the flow of gas sample through the inlet to maintain a substantially constant pressure within the ionization chamber.
公开/授权文献
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