Apparatus for measuring total pressure and partial pressure with common electron beam
US6642641B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 2001 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Jul 10, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L21/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for determining both total and partial pressures of a gas using one common electron beam includes a partial pressure ionization region and a total pressure ionization region separated by a grid or aperture. A filament produces a plurality of electrons which are focused into an electron beam by a repeller and an aperture or an anode. The interaction between the electron beam and molecules of the gas within the partial pressure and total pressure regions produces first and second ion streams. A focus plate is biased such that the first ion stream is directed to an analyzer which calculates the partial pressure of the gas. An ion collector collects the ions from the second ion stream, where the resulting reference current is used to determine the total pressure of the gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.