Eastman Chemical Company

Daniel Charles Alsmeyer

Vincent Alvin Nicely

Michael Joseph Pearce

Norma Lindsey Buchanan

Gregory Wayne Nelson

Roger Dale Edwards

Howard Smith Carman, Jr

Bruce Edwin Wilson

Carlos Humberto Juarez-Garcia

Aaron Wayne Garrett

Barry Louis Ornitz

Brinda A Gala

A safety device for detecting elastically scattered radiation comprises: an excitation source of substantially monochromatic radiation having a controllable output, a detector for detecting elastically scattered radiation collected from a specimen illuminated by the excitation source, and a signal conditioning circuit that comprises a transducer and a comparator. An output transducer signal representative of the elastically scattered radiation is compared with a predefined threshold signal. If the output transducer signal is less than the threshold signal, a control output signal coupled to the excitation source causes the output of the source to be reduced. The safety device is included in an analyzer apparatus, preferably a Raman spectrometry apparatus that further includes an optical probe. The probe comprises a fluid-tight body that encloses three optical channels, preferably comprising optical fibers, that carry monochromatic radiation to a specimen and separately collect inelastically and elastically scattered radiation from the illuminated specimen. In a method for controlling a radiation source in an analyzer apparatus, a specimen is analyzed by an excitation source having a controllable output, preferably a laser. Elastically scattered radiation from the illuminated specimen is collected, detected, and transduced into an output transducer signal representative of the scattered radiation. If the output transducer signal is less than a predefined threshold signal, a control output signal coupled to the laser causes its output to be reduced.

Elastic radiation scatter-detecting safety device analyzer apparatus

A method for providing a standard Raman spectrum from a sample uses a particular Raman spectrometry apparatus or any similar Raman spectrometry apparatus, which is used to simultaneously irradiate a reference material and at least one sample, thereby obtaining their respective convolved Raman spectra. Using a defined standard energy dispersion characteristic and a standard Raman spectrum of the reference material, a convolution function is determined and applied to produce a deconvolved Raman spectrum of the sample. This deconvolved spectrum is multiplied by a defined standard photometric response function to produce a standard Raman spectrum of the sample. A method for providing an accurate and precise quantitative analysis of the chemical composition and/or physical properties of an unknown sample uses the standard Raman spectra of a plurality of known samples to construct a normalized calibration, which is applied to a standard Raman spectrum of the unknown sample to produce an accurate and precise quantitative analysis thereof, using any similar Raman spectrometry apparatus.

Method for standardizing raman spectrometers to obtain stable and

Disclosed is a spectroscopic probe apparatus useful for Raman, near infrared, luminescence, ultraviolet or visible spectroscopies that is formed with a robust method of construction using a molten metal soldering technique. The disclosed method and apparatus provides an optical probe that is easy to manufacture yet able to withstand drastic environmental conditions without damage and produce useful spectroscopic results under such conditions.

Robust spectroscoptic optical probe

Robust spectroscopic optical probe

A method for quantitatively monitoring in situ by Raman spectrometry one or more selected constituents of a chemical composition comprises: simultaneously irradiating with a substantially monochromatic radiation source a reference material and a chemical composition containing one or more constituents, the radiation being transmitted from the source to the chemical composition by an excitation conduit connecting the source to an optical probe that interfaces with the composition; simultaneously acquiring at more than one wavelength convolved Raman spectra of the reference material and the chemical composition by means of a spectrograph, which is connected to the optical probe by a collection conduit; choosing the standard Raman spectrum of the reference material; determining the convolution function of the convolved spectra from the convolved Raman spectrum and the standard Raman spectrum of the reference material; applying the convolution function to adjust the convolved Raman spectrum of the composition to produce the standard Raman spectrum of the chemical composition; and applying predetermined calibration means to the standard Raman spectrum of the chemical composition, by which the chemical constitution of the composition at the time of acquisition of the convolved Raman spectra can be ascertained.

On-line quantitative analysis of chemical compositions by Raman

On-line quantitative analysis of chemical compositions by raman

In a process for analyzing a sample of unknown constitution by an analytical apparatus, a set of analytical measurements and a set of reference measurements, each comprising a set of multivariate signal responses obtained from a set of samples by a first and a second analytical apparatus, are adjusted to remove operational variabilities associated with the apparatus, thereby providing a first and a second matrix of adjusted signal responses. Via the use of matrix manipulations, a calibration useful for analyzing the signal responses obtained from the sample of unknown constitution by the first analytical apparatus is constructed and applied to the signal responses from the sample to determine its constitution.

Process to use multivariate signal responses to analyze a sample

A Raman spectrometry apparatus that is capable of measuring and compensating for variabilities in the apparatus comprises a source of substantially monochromatic radiation, means for simultaneously interfacing the radiation with a sample and a reference material, means for simultaneously acquiring at more than one wavelength a convolved Raman spectrum of the sample and a convolved spectrum of the reference material, and means for determining the convolution function of the convolved spectra and applying the convolution function to adjust the convolved Raman spectrum of the sample to produce thereby the standard Raman spectrum of the sample. A method for obtaining the standard Raman spectrum of a sample comprises: (a) simultaneously irradiating the sample and a reference material with a substantially monochromatic radiation source; (b) simultaneously acquiring at more than one wavelength a convolved Raman spectrum of the sample and a convolved spectrum of the reference material; (c) choosing the standard spectrum of the reference material; (d) from the convolved Raman spectrum of the sample and the convolved spectrum of the reference material and the standard spectrum of the reference material, determining the convolution function of the convolved spectra; and (e) applying the convolution function to adjust the convolved Raman spectrum of the sample to produce thereby the standard Raman spectrum of the sample.

Growing community of inventors

Kingsport, TN, United States of America

Daniel Charles Alsmeyer