Apparatus for analysis of particulate material, analytical method for same, apparatus for production of ultrapure water, apparatus for manufacturing of semiconductor, and apparatus for production of pure gas
US5316983A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1991 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Aug 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/4721
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus and a method for analysis of a particle by irradiation of the particle in a fluid with an intense laser pulse to cause laser breakdown and to detect sonic waves or plasma emission which are generated by the laser breakdown. The size of the particle is measured by using at least two kinds of information from the following: intensity of plasma emission or sonic wave generated by the laser breakdown, location of the laser breakdown plasma, and plasma emission waveform. Also, a laser pulse having flattened distribution of intensity for the irradiation is used in order to eliminate the dependence of the measured value on the particle location.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.