Single particle detector method and apparatus utilizing light extinction within a sheet of light
US5121988A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 1989 |
| Grant date | Jun 16, 1992 |
| Priority date | — |
| Expiry date | Oct 4, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/0612
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A particle flux counter apparatus utilizing light extinction. The apparatus utilizes two oppositely disposed cylindrical mirrors (21a, 21b) to bounce a beam back and forth between them, the beam traversing the length of the cylindrical mirrors (21a, 21b) in incremental steps. A plane mirror (22) is cooperatively located to reflect the beam back between the system to traverse the length of the cylindrical mirrors (21a, 21b) a second time in incremented steps. The two sets of steps interleaving such that the beam forms a sheet of light. A detector (60) monitors the intensity of the beam. As particles in a sample aerosol intersect the beam, the light is extinguished and the beam intensity changes. The detector (60) transmits a signal to a microprocessor (108) analyzation. The apparatus also utilizes a feedback circuit (300) to regulate the beam intensity and alternatively provides for modulating the beam to provide for higher peak power into the detector (60) and elimination of common mode noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.