Vacuum particle detector
US5262841A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1991 |
| Grant date | Nov 16, 1993 |
| Priority date | — |
| Expiry date | Oct 16, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/53
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A vacuum particle detector includes a cavity providing a passage for fluid flow, a laser diode and beam shaping optics to form a substantially rectangular beam spanning the chamber. Light sensing optics, including a pair of biconvex lenses, receive light scattered when the particles suspended in the fluid intersect the beam. At least some of the scattered light is transmitted through the lenses to a photodetector. The photodetector width is selected in concert with the focal lengths of the biconvex lenses, to provide a viewing depth of field commensurate with the complete span of the beam across the chamber, whereby the photodetector responds to particles that intersect the beam over the entire span. A cone and a surrounding sleeve, both concentric about an axis of the beam, absorb the laser energy beam to provide an effective beam stop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.