Photo-ionization detector for volatile gas measurement
US5773833A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 22, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Mar 22, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J41/02
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photo-ionization detector (PID) which measures volatile organic gas uses electrically insulated parallel plates to energize a miniaturized gas discharge UV lamp and an energy efficient method to modulate the UV lamp intensity and reduce power consumption. A miniaturized centrifugal pump is integrated into the PID to provide active sampling for fast response to volatile gas. An ionization chamber in the PID includes a UV shield which protects a measurement electrode from UV light and a UV monitor which measures changes in UV intensity due to external interferences and UV lamp variations. A microprocessor in the PID uses measurements from the measurement electrode and from the UV monitor to accurately account for UV intensity variations when determining a volatile gas concentration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.