Apparatus and methods for monitoring emissions
US6717153B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 2, 2001 |
| Grant date | Apr 6, 2004 |
| Priority date | — |
| Expiry date | Apr 4, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/2835
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
Ions produced by radioactive gases present in air impact on the sensitivity of contamination measuring instruments which detect ions generated by radioactive materials present on an item. Methods and apparatus address this issue by conducting a measurement of ions generated in a chamber by gaseous emitters and other background events in a volume of medium and deducting this from a measurement of ions generated in another chamber by the item as well as the gaseous emitters and background events. The variation of the gaseous emitters present within the medium is addressed by moving the medium about. An alternative solution uses a medium free of gaseous emitters having a significant level, for instance by sealed storage of air prior to its use in a method and instrument.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.