Dispersive near-infrared spectrometer with automatic wavelength calibration
US6774368B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2002 |
| Grant date | Aug 10, 2004 |
| Priority date | — |
| Expiry date | May 6, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2003/2866
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention is a dispersive, diffraction grating, NIR spectrometer that automatically calibrates the wavelength scale of the instrument without the need for external wavelength calibration materials. The invention results from the novel combination of: 1) a low power He—Ne laser at right angles to the source beam of the spectrometer; 2) a folding mirror to redirect the collimated laser beam so that it is parallel to the source beam; 3) the tendency of diffraction gratings to produce overlapping spectra of higher orders; 4) a “polka dot” beam splitter to redirect the majority of the laser beam toward the reference detector; 5) PbS detectors and 6) a software routine written in Lab VIEW that automatically corrects the wavelength scale of the instrument from the positions of the 632.8 nm laser line in the spectrum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.