Photometric instruments, their use in methods of optical analysis, and ancillary devices therefor
US4810658A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 1986 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Feb 13, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/7786
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of optical analysis of a test sample which comprises a sample material with light-absorbing, scattering, fluorescent, phosphorescent or luminescent properties, which sample is partly in a liquid phase and partly bound to an adjacent solid surface, to discriminate the respective parts of said sample material which are located in the liquid and bound to said solid surface: comprising the steps of providing as said solid surface a surface of a transparent solid optical waveguide, and measuring light from the sample material bound to said solid surface that has passed into and through said transparent solid optical waveguide with total internal reflections and emerged from said waveguide at an angle that deviates from the optical axis of said waveguide by an angle appreciably less than .alpha., where EQU .alpha.=arcsin.sqroot.(n.sub.2.sup.2 -n.sub.1.sup.2) where n.sub.2 is the refractive index of the material of the waveguide and n.sub.1 is the refractive index of the adjacent liquid, the excluding from said measurement substantially all light that has emerged from said waveguide at an angle that deviates from said optical axis by .alpha. or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.