Ambient light suppression for reflectance photometers
US5189495A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1991 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Sep 3, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/064
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A spectral cover for a reflectance photometer is disclosed in which the spectral cover is designed to cover the readhead area of the reflectance photometer and block the transmission of light in a wavelength range of at least 60 to no more than 200 nanometers centered about the detection wavelength while permitting light of other wavelengths to be transmitted. The invention permits the readhead cover to be permanently or semipermanently positioned on the reflectance photometer. Since a user is able to see through the spectral cover it is possible to position a test device correctly and quickly over the readhead of the reflectance photometer. Signal noise levels due to ambient light are substantially eliminated by the invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.