Method and apparatus for analyzing a gas sample
US5412207A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1993 |
| Grant date | May 2, 1995 |
| Priority date | — |
| Expiry date | Oct 7, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/4215
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and gas analysis system for a mass spectrometer including an ion pump for creating an internal vacuum within said mass spectrometer, an ionization chamber, an inlet passage through which a gas sample is introduced into the ionization chamber, valve means associated with the inlet passage for controlling the volume of gas sample introduced into the ionization chamber, a filament for introducing electrons into the ionization chamber whereby the electrons bombard the gas sample thus forming ions, an extractor plate positioned adjacent the ionization chamber and biased such that a proportion of ions and electrons are allowed to pass through the extractor plate, a quadrupole filter into which the ions and electrons are directed by the extractor plate, the quadrupole filter operative to permit a stream of ions with a pre-selected mass-to-charge ratio to pass through the filter and ions other than those having the pre-selected mass-to-charge ratio being separated from the stream of ions, means for directing electrons toward ions other than those having the pre-selected mass-to-charge ratio in the area of said quadrupole filter so that the electrons combine with the ions, a sensor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.