System to reduce wave shift error in spectrophotometer caused by hot spots in the light source
US5055684A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 6, 1989 |
| Grant date | Oct 8, 1991 |
| Priority date | — |
| Expiry date | Dec 6, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/0205
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved near infrared spectrophotometer is disclosed which reduces wave shift errors arising from hot spots in a light source. A ground quartz plate uniformly diffuses radiation from the light source to evenly illuminate the entrance slit for a diffraction grating. Radiation emerges from the entrance slit with a uniform angular intensity distribution and is dispersed into a spectrum by a reflecting diffraction grating towards an exit slit. A narrow wavelength band of radiation passes through the exit slit to illuminate a sample. Because the entrance slit is uniformly illuminated, without regard to variations in radiation intensity due to hot spots in the source, wave shift errors in the reflectivity measurements for the sample are reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.