Xiaoyong Liu - Malden MA, US John McKinley Poole - Maynard MA, US Yufeng Huang - North Chelmsford MA, US Daniel M. Stearns - Canton MA, US Michael J. Gambuzza - Pepperell MA, US Gene Smith Berkowitz - Sudbury MA, US Anthony Kowal - Berlin MA, US Hejie Li - Schenectady NY, US Shawn D. Wehe - Niskayuna NY, US
Assignee:
GE Infrastructure Sensing, Inc. - Billerica MA
International Classification:
G01N 21/31
US Classification:
356435, 250345
Abstract:
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. In another embodiment, the spectroscopy apparatus comprises a beam splitter configured to split the laser radiation into a first radiation portion and a second radiation portion and a first photodetector configured to detect the intensity of the first radiation portion.
Method Of Calibrating A Wavelength-Modulation Spectroscopy Apparatus Using A First, Second And Third Gas To Determine Temperature And Pressure Values To Calculate Concentrations Of Analytes In A Gas
Xiaoyong Liu - Malden MA, US Yufeng Huang - North Chelmsford MA, US John McKinley Poole - Maynard MA, US Gene Smith Berkowitz - Sudbury MA, US Anthony Kowal - Berlin MA, US Shawn D. Wehe - Niskayuna NY, US Hejie Li - Schenectady NY, US
Assignee:
GE Infrastructure Sensing, Inc. - Billerica MA
International Classification:
G01V 8/00 G01J 3/28
US Classification:
2505591, 356326
Abstract:
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.
Method Of Calibrating A Wavelength-Modulation Spectroscopy Apparatus Using A First, Second, And Third Gas To Determine Temperature Values To Calculate Concentrations Of An Analyte In A Gas
Xiaoyong Liu - Malden MA, US Yufeng Huang - North Chelmsford MA, US John McKinley Poole - Maynard MA, US Gene Smith Berkowitz - Sudbury MA, US Anthony Kowal - Berlin MA, US Shawn D. Wehe - Niskayuna NY, US Hejie Li - Schenectady NY, US
Assignee:
GE Infrastructure Sensing, Inc. - Billerica MA
International Classification:
G01V 8/00 G01J 3/28
US Classification:
2505591, 356326
Abstract:
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.
Method Of Calibrating A Wavelength-Modulation Spectroscopy Apparatus
Xiaoyong Liu - Malden MA, US Yufeng Huang - North Chelmsford MA, US John McKinley Poole - Maynard MA, US Gene Smith Berkowitz - Sudbury MA, US Anthony Kowal - Berlin MA, US Shawn D. Wehe - Niskayuna NY, US Hejie Li - Schenectady NY, US
International Classification:
G01N 21/17
US Classification:
73 103, 73 106
Abstract:
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.
Methods, devices, and systems are provided for analyzing the moisture content in natural gas. In one embodiment, a portable moisture analyzer system is provided and can include a moisture analyzer and a housing. The moisture analyzer can include a tunable diode laser absorption spectrometer (TDLAS) and a natural gas sample conditioning system. The TDLAS can be configured to detect water vapor content within a natural gas sample. The sample conditioning system can be in fluid communication with the TDLAS and can be configured to condition at least one of temperature, flow rate, and pressure of a natural gas sample. The housing can be configured to receive the moisture analyzer therein and to protect the moisture analyzer from vibration and/or shock.
- Bellerica MA, US John Poole - Billerica MA, US Aniruddha Sudheer Weling - Billerica MA, US Gene Berkowitz - Billerica MA, US
International Classification:
G01N 21/39 G01N 33/00 G01N 21/01 G01N 1/34
Abstract:
Methods, devices, and systems are provided for analyzing the moisture content in natural gas. In one embodiment, a portable moisture analyzer system is provided and can include a moisture analyzer and a housing. The moisture analyzer can include a tunable diode laser absorption spectrometer (TDLAS) and a natural gas sample conditioning system. The TDLAS can be configured to detect water vapor content within a natural gas sample. The sample conditioning system can be in fluid communication with the TDLAS and can be configured to condition at least one of temperature, flow rate, and pressure of a natural gas sample. The housing can be configured to receive the moisture analyzer therein and to protect the moisture analyzer from vibration and/or shock.