Patents by Inventor Shawn D. Wehe
Shawn D. Wehe has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8217376Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.Type: GrantFiled: April 11, 2011Date of Patent: July 10, 2012Assignee: GE Infrastructure Sensing, Inc.Inventors: Xiaoyong Liu, Yufeng Huang, John McKinley Poole, Gene Smith Berkowitz, Anthony Kowal, Shawn D. Wehe, Hejie Li
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Patent number: 8026499Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.Type: GrantFiled: April 11, 2011Date of Patent: September 27, 2011Assignee: GE Infrastructure Sensing, Inc.Inventors: Xiaoyong Liu, Yufeng Huang, John McKinley Poole, Gene Smith Berkowitz, Anthony Kowal, Shawn D. Wehe, Hejie Li
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Publication number: 20110181877Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is, accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.Type: ApplicationFiled: April 11, 2011Publication date: July 28, 2011Inventors: Xiaoyong Liu, Yufeng Huang, John McKinley Poole, Gene Smith Berkowitz, Anthony Kowal, Shawn D. Wehe, Hejie Li
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Publication number: 20110181876Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.Type: ApplicationFiled: April 11, 2011Publication date: July 28, 2011Inventors: Xiaoyong Liu, Yufeng Huang, John McKinley Poole, Gene Smith Berkowitz, Anthony Kowal, Shawn D. Wehe, Hejie Li
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Patent number: 7957001Abstract: In one embodiment of the spectroscopy method, the method comprises the steps of modulating the wavelength of a monochromatic radiation at a modulation amplitude and a modulation frequency; determining a first variable representative of an absorbance of an analyte in a sample; and demodulating by phase-sensitive detection the first variable at a harmonic of the modulation frequency to produce a harmonic spectrum of the analyte. In one embodiment of the spectroscopy apparatus, the apparatus comprises a laser diode integrated with a first photodetector configured to detect an intensity of a backward emission from the laser diode and act as a reference detector; a second photodetector configured to detect an intensity of laser radiation exiting a sample; and electronic circuitry coupled to the laser diode and the photodetectors, configured to acquire and process spectra of the sample.Type: GrantFiled: October 10, 2008Date of Patent: June 7, 2011Assignee: GE Infrastructure Sensing, Inc.Inventors: Xiaoyong Liu, John McKinley Poole, Yufeng Huang, Daniel M. Stearns, Michael J. Gambuzza, Gene Smith Berkowitz, Anthony Kowal, Hejie Li, Shawn D. Wehe
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Patent number: 7943915Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.Type: GrantFiled: October 10, 2008Date of Patent: May 17, 2011Assignee: GE Infrastructure Sensing, Inc.Inventors: Xiaoyong Liu, Yufeng Huang, John McKinley Poole, Gene Smith Berkowitz, Anthony Kowal, Shawn D. Wehe, Hejie Li
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Publication number: 20100089117Abstract: Several methods of calibrating a wavelength-modulation spectroscopy apparatus configured to measure a concentration of an analyte in a sample gas are disclosed. Each of the methods allows for calibration and recalibration using a relatively safe gas regardless of whether the sample gas for which the concentration of the analyte can be determined is a hazardous gas. In one embodiment of the invention, calibration that is sample-gas specific is accomplished by determining a first slope coefficient and calibration function for the sample gas, after which a scaling factor can be determined based on the first slope coefficient and a second slope coefficient for the same or a different sample gas and used in a subsequent calibration (or recalibration) to scale the calibration function. In other embodiments of the invention, calibration that is not sample-gas specific is accomplished to allow for the determination of the analyte concentration in variable gas compositions and constant gas compositions.Type: ApplicationFiled: October 10, 2008Publication date: April 15, 2010Inventors: Xiaoyong Liu, Yufeng Huang, John McKinley Poole, Gene Smith Berkowitz, Anthony Kowal, Shawn D. Wehe, Hejie Li
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Publication number: 20100091278Abstract: In one embodiment of the spectroscopy method, the method comprises the steps of modulating the wavelength of a monochromatic radiation at a modulation amplitude and a modulation frequency; determining a first variable representative of an absorbance of an analyte in a sample; and demodulating by phase-sensitive detection the first variable at a harmonic of the modulation frequency to produce a harmonic spectrum of the analyte. In one embodiment of the spectroscopy apparatus, the apparatus comprises a laser diode integrated with a first photodetector configured to detect an intensity of a backward emission from the laser diode and act as a reference detector; a second photodetector configured to detect an intensity of laser radiation exiting a sample; and electronic circuitry coupled to the laser diode and the photodetectors, configured to acquire and process spectra of the sample.Type: ApplicationFiled: October 10, 2008Publication date: April 15, 2010Inventors: Xiaoyong Liu, John McKinley Poole, Yufeng Huang, Daniel M. Stearns, Michael J. Gambuzza, Gene Smith Berkowitz, Anthony Kowal, Hejie Li, Shawn D. Wehe
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Patent number: 7683357Abstract: A gas species monitoring system includes a laser, a fiber amplifier configured to receive an input signal from the laser and generate an amplified signal, and a variable optical attenuation system configured to receive at least a portion of the amplified signal and generate an attenuated signal for delivery to a measurement point, where the measurement point includes a gaseous fluid. The system further includes a detector configured to receive and process a signal from the measurement point so as to obtain a measured signal that correlates with the presence of a gas species within the gaseous fluid at the measurement point, and a processor in communication with at least the variable optical attenuation system and the detector. The processor controls the variable optical attenuation system based upon the measured signal.Type: GrantFiled: July 1, 2008Date of Patent: March 23, 2010Assignees: American Air Liquide, Inc., Physical Sciences, Inc.Inventors: William A. Von Drasek, Shawn D. Wehe, Mark G. Allen
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Publication number: 20080265142Abstract: A gas species monitoring system includes a laser, a fiber amplifier configured to receive an input signal from the laser and generate an amplified signal, and a variable optical attenuation system configured to receive at least a portion of the amplified signal and generate an attenuated signal for delivery to a measurement point, where the measurement point includes a gaseous fluid. The system further includes a detector configured to receive and process a signal from the measurement point so as to obtain a measured signal that correlates with the presence of a gas species within the gaseous fluid at the measurement point, and a processor in communication with at least the variable optical attenuation system and the detector. The processor controls the variable optical attenuation system based upon the measured signal.Type: ApplicationFiled: July 1, 2008Publication date: October 30, 2008Inventors: William A. VON DRASEK, Shawn D. Wehe, Mark G. Allen
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Patent number: 7409117Abstract: A gas species monitoring system includes a laser, a fiber amplifier configured to receive an input signal from the laser and generate an amplified signal, and a variable optical attenuation system configured to receive at least a portion of the amplified signal and generate an attenuated signal for delivery to a measurement point, where the measurement point includes a gaseous fluid. The system further includes a detector configured to receive and process a signal from the measurement point so as to obtain a measured signal that correlates with the presence of a gas species within the gaseous fluid at the measurement point, and a processor in communication with at least the variable optical attenuation system and the detector. The processor controls the variable optical attenuation system based upon the measured signal.Type: GrantFiled: January 31, 2005Date of Patent: August 5, 2008Assignees: American Air Liquide, Inc., Physical Sciences, Inc.Inventors: William A. Von Drasek, Shawn D. Wehe, Mark G. Allen
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Publication number: 20040027575Abstract: A method to provide user selected tunability for multi-section lasers manufactured for the telecommunication industry is disclosed. Extending the tunability of the laser to be user selectable provides a means to use the technology in other applications such as gas sensing or optical component testing. The combination of the broad tuning range with rapid wavelength selection will permit a reduction in the number of DFB lasers used in multiplexed systems thereby reducing system cost and complexity.Type: ApplicationFiled: January 29, 2003Publication date: February 12, 2004Inventors: William A. Von Drasek, Shawn D. Wehe, Mark G. Allen
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Publication number: 20030132389Abstract: A method for monitoring the high temperature reducing combustion atmosphere in a combustion process is disclosed. First, a spectral region for monitoring CO and H2O is identified. A laser wavelength is scanned so that a complete absorption transition includes a portion of the baseline. A laser is then referenced to an ITU-GRID. An output signal is generated from the laser and directed to a coupler to split the output signal in a predetermined ratio to a first component and a second component. The first component is directed to optics where it is shaped and collimated and then directed across a sample to be monitored to a detector that generates a measured output. The second component is directed to an absorption measurement device. The measured output is compared with the second component, and the temperature of the atmosphere and the concentration of the CO present in the atmosphere is calculated.Type: ApplicationFiled: December 9, 2002Publication date: July 17, 2003Inventors: William A. Von Drasek, Shawn D. Wehe, Mark G. Allen