Two-beam photometer with rotatable graded interference filter
US4017191A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1975 |
| Grant date | Apr 12, 1977 |
| Priority date | — |
| Expiry date | Jun 20, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2003/1234
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The two-beam photometer is suitable for extinction measurement on weakly-absorbent samples. The principle of measurement is based on a wavelength selection in either the comparison beam and the measuring beam. In the beam configuration measuring and comparison beam are coincident in space and follow each other periodically. The wavelength ranges in measuring beam and comparison beam is selected by a graded interference filter which is arranged perpendicular to the optical axis and rotatable about this axis. In the zone of the graded interference filter the path of the beam is formed by two narrowly limited beams symmetrically to the optical axis. Both beams are produced preferably by two light sources whose distance may be varied in a direction perpendicular to the optical axis while the symmetry with respect to the optical axis is maintained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.