Method and apparatus for near infrared reflectance measurement of non-homogeneous materials
US4801804A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 1986 |
| Grant date | Jan 31, 1989 |
| Priority date | — |
| Expiry date | Sep 30, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S250/91
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for near infrared reflectance measurement of non-homogeneous materials. Constituents of a material are quantitatively analyzed by reflectance techniques utilizing a planar surface of the material within a cup-shaped sample holder opaque to near-infrared radiation. A predetermined area of the planar surface is uniformly irradiated with near infrared radiation emitted from a source spaced a predetermined distance away from the planar surface. Near infrared radiation reflected by substantially all of the predetermined surface area is detected with a near infrared radiation detector spaced a predetermined distance away from the planar surface, to provide a signal which is processed to measure an average content of a constituent in the sample material. The source and detector are contained in a probe which is calibrated by inserting the probe into a cavity. The probe is spaced from the bottom of the cavity such that the cavity reflectance is about equal to that of the material for which the probe is being calibrated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.