System for identifying materials by NIR spectrometry
US5822219A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1996 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | May 13, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG16C20/20
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a method for identifying an unknown product a library of absorbance spectra of known products is measured and stored in a library. A quick search using clustering techniques is conducted to narrow the search to a few products, followed by an exhaustive search of the spectra of the few products. More specifically, principal component analysis is applied to the absorbance spectra to generate product score vectors extending into principal component inside model space which are divided into clusters and subclusters in accordance with their relative proximity. Hyperspheres are constructed around each vector and an envelope is constructed to enclose each cluster surrounding the hyperspheres within the cluster. The absorbance spectrum of the unknown product to be identified is measured and an unknown product score vector is determined from the unknown product spectrum projecting in principal component inside model space of the clusters. It is determined whether or not the unknown product score vector falls within one of the envelopes and if so the product score vector is projected into the principal component inside model space of that cluster and it is determined whether or not the un…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.