Abstract: A transverse optical transmission probe having a probe body and a probe tip. The probe use optical fibers to both transmit radiation from an instrument to the probe tip and to return the sample affected radiation to the instrument. The fibers are in parallel and contained in the probe body. The probe tip includes two optical elements that protrude into the sample and are configured to define a sample gap so that incident radiation pass through the sample in a direction transverse to the axis to the probe and eventually reaches the receiving fiber. Each of the optical elements may be formed from a single piece of material or may be a composite formed by adhering two or more pieces of material together. One or more lensed surfaces may be used to cause the end of the transmitting fiber to be imaged on the end of the receiving fiber.

Abstract: A spectroscopic measuring device for minimizing spurious absorption due to undesired gases. The device includes a probe body, or a transmission cell formed from a central measurement cell and first and second probe bodies. Each probe body is subject to leakage of undesired gas, especially over time in the presence of high pressure gas. Each probe body includes a bore located between a primary window disposed at or near a distal end and a secondary window located at or near the proximal end. It being observed that the absorbance is proportional to the pathlength and inversely proportional to the volume as long as the pressure in the probe body remains low compared to that in the measurement cell, a glass filler rod is located in the bore and a is void located adjacent to the filler glass rod, thereby minimizing spurious absorption even in the presence of leakage.

Abstract: A transverse optical transmission probe having a probe body and a probe tip. The probe use optical fibers to both transmit radiation from an instrument to the probe tip and to return the sample affected radiation to the instrument. The fibers are in parallel and contained in the probe body. The probe tip includes two optical elements that protrude into the sample and are configured to define a sample gap so that incident radiation pass through the sample in a direction transverse to the axis to the probe and eventually reaches the receiving fiber. Each of the optical elements may be formed from a single piece of material or may be a composite formed by adhering two or more pieces of material together. One or more lensed surfaces may be used to cause the end of the transmitting fiber to be imaged on the end of the receiving fiber.

Abstract: A spectroscopic measuring device for minimizing spurious absorption due to undesired gases. The device includes a probe body, or a transmission cell formed from a central measurement cell and first and second probe bodies. Each probe body is subject to leakage of undesired gas, especially over time in the presence of high pressure gas. Each probe body includes a bore located between a primary window disposed at or near a distal end and a secondary window located at or near the proximal end.

Abstract: A multi-pass gas cell that operates with reflected radiation pass through a gas, the reflected radiation transmitted and received by first and second fiber optic ports that are subject to an alignment adjustment, and a mirrored viewing window having a inner reflective surface exposed to an interior of the elongated cell body for reflecting the radiation within the cell body, an outer viewing surface, and a transmittance characteristic that permits a portion of the radiation to pass through the mirrored window, from the inner reflective surface to the outer viewing surface, as a visual indicator of the alignment condition of the reflected radiation relative to the first and second fiber-optic ports.

Abstract: A probe for use in Raman spectroscopy that can be inserted into a chemical vessel through a small diameter fitting while maximizing the amount of Raman shifted radiation collected and minimizing spurious effects.

Abstract: A multipass system for sampling by Raman spectroscopy enhances the collected signal and provides a system having improved sensitivity. The system incorporates an injection element for inserting collimated excitation radiation into an optical path, an objective lens for focusing the excitation radiation into the sample and for collecting radiation, a blocking filter that is substantially perpendicular to the optical path and that transmits Raman shifted radiation and reflects the excitation radiation, and a mirror for causing the excitation radiation to reflect excitation radiation back and forth between the mirror and the blocking filter multiple times while Raman shifted radiation is passed through the blocking filter for collection and analysis.

Abstract: A probe for use in Raman spectroscopy that can be inserted into a chemical vessel through a small diameter fitting while maximizing the amount of Raman shifted radiation collected and minimizing spurious effects.

Abstract: The invention relates to a fiber-optic coupled diffuse reflectance probe that is adapted to detachably connect to a bifurcated fiber bundle. The probe includes a solid light guide for separating the bundle from the target within a small-diameter probe body. A probe of this construction is especially useful for analyzing high temperature and high pressure targets, through relatively small fittings, as is required in polymer extrusion applications. The solid light guide may extend along all or along a lesser portion of the probe body's length. Its fiber-end may be coupled directly to the illumination and detector fibers or indirectly, and at some distance from the fibers, by way of a lens or a hollow light guide. Its target-end may be exposed to terminate in a direct face-to-face relationship with the target, or it may be located behind an intermediate window. The solid light guide is characterized by a target-end refracting surface that minimizes stray light.

Abstract: A multipass system for sampling by Raman spectroscopy enhances the collected signal and provides a system having improved sensitivity. The system incorporates an injection element for inserting collimated excitation radiation into an optical path, an objective lens for focusing the excitation radiation into the sample and for collecting radiation, a blocking filter that is substantially perpendicular to the optical path and that transmits Raman shifted radiation and reflects the excitation radiation, and a mirror for causing the excitation radiation to reflect excitation radiation back and forth between the mirror and the blocking filter multiple times while Raman shifted radiation is passed through the blocking filter for collection and analysis.

Abstract: The invention is an optical switching device having a switching element which, in one aspect is a solid switching body to reduce beam spread, in a second aspect is trapezoidal in cross-section so that the optical channels selectively connected by the switching body are conveniently located on one side of the device, and in a third aspect is a retroreflective switching element that eliminates the need to achieve and maintain precise angular alignment between the switching body and the optical axes of the optical channels connected by the switching device.

Abstract: A sample immersion probe is disclosed which has an ATR (attenuated total reflectance) element at its tip. The ATR is so shaped that radiation exiting the probe will travel in paths parallel to radiation entering the probe. The angles of incidence of radiation on the ATR surface (or surfaces) which permit partial absorption by the sample material are greater than 45.degree.. At least one of the ATR surfaces in contact with the sample has a fully reflecting coating which prevents radiation absorption by the sample at that location. The ATR shape may be symmetrical or non-symmetrical with respect to the axis of symmetry of the probe. The radiation entering the probe may be in a separate light guide (i.e., path) from the radiation exiting the probe; or the entering and exiting radiation may be in the same light guide (path).

Abstract: The invention relates to a fiber-optic coupled diffuse reflectance probe that is adapted to detachably connect to a bifurcated fiber bundle. The probe includes one or more lenses for imaging the bundle onto a target with more space between the bundle and the target than otherwise possible. The collecting lens adjacent to the bundle preferably has a reflection stop which diverts reflected light away from the bundle to minimize the problem of stray light. The preferred probe also uses an objective lens to increase the distance between the bundle and the target. The rays emerging from the collecting lens will diverge or spread because of the finite diameter of the transmitting fibers in the bundle.

Abstract: A sensing apparatus for spectral analysis in which the sensing head is bi-layered. The layer contacting the sample is formed of corrosion-resistant material, e.g., diamond. It is engaged by a supporting layer formed of infrared transparent material, e.g., zinc selenide through which radiation passes on its way to and from the sample-contacting layer. In order to avoid non-linearity in the sample absorbance results, incoming paraxial rays are all reflected in such a way that they are reflected at the same angle, and the same number of times, from the sample contacting surface of the corrosion resistant layer. The incoming rays may be reflected at a conical surface, or at a flat rooftop-like surface. The exiting rays are preferably reflected so that they are parallel to the incoming rays. Where a conical reflecting surface is used, it may be a surface of the zinc selenide layer, or a highly reflective surface provided by another element.

Abstract: A method is for expanding the solute-identifying capabilities of an infrared (IR) sparging system. In IR-sparging, bubbles transfer solutes contained in a volume of liquid to a gas stream which is analyzed in a gas cell. FTIR spectrometry provides spectral absorbance analysis to identify and measure the solutes. By repeating the spectral scans at given time intervals, data is also obtained which is related to the depletion rate curves of the respective solutes. Using this depletion rate data to complement the spectral analysis data provides major benefits in successfully identifying the solutes.

Abstract: An immersion probe (for powder or liquid) is disclosed comprising an ATR element supported at the bottom of a radiation-confining tube. The ATR element has a sample-entering tip which is either conical (preferably) or roof-top shaped. The ATR element causes entering radiation to be reflected twice by its sample-engaging surfaces, where attenuation due to the sample material occurs. The ATR element also acts as a retroreflector, causing the exiting radiation to follow a path parallel to the entering radiation. In order to avoid spurious results due to reflection by the rear surface of the ATR element, its rear surface is cone shaped or rooftop shaped, using a large apex angle.

Abstract: A sparging-infrared liquid analyzing system having a vessel in which a gas stream makes a single pass through a liquid stream containing contaminants, in order to provide vapor-to-liquid equilibrium of contaminants in the gas stream. The gas stream is then passed through a condenser, in which the gas temperature is precisely controlled, and the gas is cooled to a point below the dew point of water vapor in the gas stream. The gas is then flowed into a gas cell for infrared analysis. Water vapor effects are removed from the analytical output. Also, the effects of excessive depletion of relatively insoluble contaminants are removed from the analytical output.

Abstract: A probe for liquid sample analysis is disclosed which causes radiation to pass through the sample at a gap formed in the probe housing. A single radiation transmission is used to avoid problems of radiation back scatter and sample reliability. Windows are provided on opposite sand and and and and and and ides of the gap to accommodate the shape of the beam in the gap, which may either be collimated, or focused in the gap. A retroreflector may be used to reverse the radiation direction in the probe. The light to and from the probe is preferably transmitted by optical fiber cables. Within the probe, light guides other than optical fibers may be used.

Abstract: An infrared microscope is disclosed which provides illumination for reflectance by the sample. This illumination follows a path through the objective toward the sample, and again, after reflection, through the objective toward the detector The reflectance illumination is directed toward the objective and sample by a fully reflective mirror, which injects approximately half of the interferometer beam into the microscope, and permits substantially all of the reflected beam to reach the detector.

Abstract: A probe for use in Raman spectroscopy that can be inserted into a chemical vessel through a small diameter fitting while maximizing the amount of Raman shifted radiation collected and minimizing spurious effects.