Photo-ionization detector and method for continuous operation and real-time self-cleaning
US6734435B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 2001 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | Jun 8, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/0047
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photo-ionization detector (PID) including two detection units controls gas flows through the ionization chambers of the detection units for real-time self-cleaning and measurement. Operation of the PID can include flowing gas through the ionization chamber of one detection unit to measure the volatile gas concentration while stopping gas flow through the ionization chamber of the other detection unit. A UV lamp converts oxygen contained in the closed ionization chamber to ozone, which removes contamination in the closed ionization chamber, Continuous gas flows can alternate between one ionization chamber to the other. Alternatively, a PID with only one gas detection unit intermittently interrupts the flow of the ambient gas in the ionization chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.