Raman spectroscopy apparatus and method for continuous chemical analysis of fluid streams
US5751415A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 1996 |
| Grant date | May 12, 1998 |
| Priority date | — |
| Expiry date | May 13, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/651
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus and methods for analyzing the chemical composition of fluid streams using Raman spectroscopy are disclosed. The invention is particularly useful in continuously analyzing a fluid stream containing petroleum products, aqueous or biological fluids. The apparatus includes a laser source for producing light having an excitation wavelength. The light is introduced into a bundle of optical fibers connected to a tubular Raman enhancement cell. A transparent optical element (lens and/or window) acts as a barrier element to isolate the flowing sample stream from the optical components. The Raman enhancement cell is configured to allow continuous sample fluid flow therethrough, and it is preferably lined with a material having an index of refraction less than the index of refraction of the fluid stream. Scattered light from the enhancement cell preferably exits the optical fibers as a linear optical signal. A Raman spectrometer passes the optical signal through an excitation wavelength filter, an optical slit, and a volume holographic transmission grating with an aberration correction device before transmitting the optical signal to a charge coupled device array which converts the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.