Method and apparatus for measuring particles in a fluid
US4830494A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 1987 |
| Grant date | May 16, 1989 |
| Priority date | — |
| Expiry date | Jul 9, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/4707
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is a method and apparatus for measuring particles in a fluid by irradiating the fluid containing the particle with a laser beam and analyzing the laser light scattered by the particle to determine the characteristics of the particle. An elliptical laser beam is projected into a particle detection area in which the particles to be measured are caused to flow. The laser light scattered by the particle is received for photoelectric conversion into a time-series photoelectric signal in a direction along which the particle flows. The photoelectric signal is subjected to a moving average process to determine a time width during which the signal exceeds a predetermined level to cause the change in intensity of the scattered light. This change is recognized as a change in intensity caused by the passage of the particle through the particle detection area when the time width falls within a certain range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.