Abstract: A method and system for examining the composition of a fluid or solid sample using fluorescence and/or absorption spectroscopy. In one embodiment, the system is adapted for use in examining liquid effluents as they elute from the end of a liquid chromatography column and comprises a Nd:YAG laser coupled to a harmonic generator. Pulses of the fourth harmonic therefrom are focused into a Raman shifter filled with a mixture of hydrogen and methane gases. The laser pulses have an intensity sufficient to produce an array of different-colored laser pulses by stimulated Raman scattering within the Raman shifter. These different-colored pulses are then dispersed according to their respective wavelengths and then launched into a plurality of optical fibers. The fibers tranmit the different-colored pulses to a specially-designed detection cell, where they simultaneously excite a flowing fluid sample contained within the cell at the same point of axial fluid flow.

Abstract: The present invention relates to generation of pulsed supersonic gas flow through a slit-shaped nozzle, useful in a wide range of applications, including particle separation, wind-tunnel studies, and especially spectroscopic studies of cold, gas-phase molecules. Specifically, the present invention is directed to a pulsed slit nozzle, which has a high length to width ratio, affording high sensitivity in spectroscopic applications.In addition, the present invention provides low dead volume, superior sealing properties, ease of actuation, heatability, uniform flow, ease of construction and maintenance, chemical inertness and long life.

Abstract: Subsurface contaminants are readily and inexpensively detected and measured by means of a test head positioned at the subsurface site and forming a protected test chamber for the liquids to be tested. The head encloses the end faces of fiber optic elements which carry radiation to the liquid sample from a test instrument located at the surface and which return radiation from the sample to the instrumentation. A connector positioned at the surface decouples the head from the instrumentation, so that the same instrumentation can service a larger number of test sites.