Combined transmittance and angle selective scattering measurement of fluid suspended particles for simultaneous determination of refractive index, extinction coefficient, particle size and particle density
US7999936B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2009 |
| Grant date | Aug 16, 2011 |
| Priority date | — |
| Expiry date | Nov 16, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/4133
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The refractive index, extinction coefficient, size and density of fluid suspended particles are simultaneously determined by combined transmittance and scattering measurements. The scattering measurements are preferably angle selective to obtain additional information about the scattered light. A charge-coupled device is employed for its high sensitivity to low light intensity in measurement of scattered light in combination with a photodiode array employed for its high signal to noise ratio, which is beneficial in transmittance measurement. The scattered light may be measured in an angle selective fashion by use of a motorized aperture that is concentrically positioned with respect to the impinging beam axis and moveable along the impinging beam axis. An ellipsoidal mirror collects the scattered light that passes through the motorized aperture and focuses the scattered light towards the charge-coupled device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.