Industrial Raman: Providing easy, immediate, cost-effective, chemical analysis anywhere

During the past decade Raman spectroscopy has moved out of the shadow of infrared spectroscopy and has become a routine laboratory tool for chemical analysis. This is largely due to the development of stable diode lasers, fiber optic sample probes, compact optical designs (full spectra without scanning), high quantum efficiency detectors, and personal computers with fast electronics, and associated data acquisition and analysis. These developments allow real-time (one minute or less), multi-component chemical analysis, and suggest the use of Raman spectroscopy for process monitoring and control. Single-ended fiber optic probes simplify coupling into process streams, allow remote placement of the Raman instrument from the sample point, and give Raman spectroscopy a decided advantage over infrared spectroscopy in industrial liquid and solid process applications. Indeed, more than a dozen new Raman instrument companies offering fiber optic based systems have been launched in the past five years. Notably, all of these systems employ charge coupled device detectors. And yet, only one company has successfully penetrated the industrial market. Instrument limitations cited include fluorescence interference, incomplete spectral coverage (particularly CH and OH regions), wavelength reproducibility, and long-term instrument stability. To address these limitations, Real-Time Analyzers has developed a Fourier transform Raman instrument. It employs a diode pumped Nd:YAG laser with excitation at 1064 nm and a single element, uncooled InGaAs detector, that are integrated into On-Line Technologies' proven rugged, vibration and temperature immune interferometer. Instrument design and industrial applications will be presented.