Abstract: A method for baseline calibration of methane sensor includes receiving data characterizing methane detection by a sensor and sensor measurement parameters. The received data characterizing methane detection includes a plurality of methane measurements and detection times associated with the plurality of methane measurements. The method also includes determining a first plurality of calibrated methane measurements by at least calibrating the plurality of methane measurement based on the sensor measurement parameters and one or more of a humidity and a temperature associated with the sensor. The method further includes calculating an offset parameter based on a difference between a global baseline reference and one of a previous baseline value and a measurement baseline value associated with the first plurality of calibrated methane measurements.

Abstract: A method for baseline calibration of methane sensor includes receiving data characterizing methane detection by a sensor and sensor measurement parameters. The received data characterizing methane detection includes a plurality of methane measurements and detection times associated with the plurality of methane measurements. The method also includes determining a first plurality of calibrated methane measurements by at least calibrating the plurality of methane measurement based on the sensor measurement parameters and one or more of a humidity and a temperature associated with the sensor. The method further includes calculating an offset parameter based on a difference between a global baseline reference and one of a previous baseline value and a measurement baseline value associated with the first plurality of calibrated methane measurements.

Abstract: A method of in situ ultrasonic flow meter validation includes receiving data characterizing first signal diagnostics and data characterizing a first speed of a first acoustic signal through a gas mixture along a first path in a pipe. The first speed of the first acoustic signal is detected by a first channel of an ultrasonic flow meter including a first pair of transducers that are separated by a first path length of the first path. The gas mixture is configured to flow along a flow path in the pipe. The method also includes determining a status associated with the ultrasonic flow meter based on the data characterizing the first signal diagnostics and/or a difference between the first speed of the first acoustic signal and an independently calculated speed of sound. The speed of sound is calculated based on one or more properties of the gas mixture.

Abstract: Systems and methods for monitoring emissions of a combusted gas are provided. The method includes determining a first net heating value of a flare gas. The method also includes determining a second net heating value of a combustion gas including the flare gas. The second net heating value can be determined based upon the first net heating value and a volumetric flow rate of the flare gas. Based upon the value of the second net heating value, an empirical model or a non-parametric machine learning model can be selected. A combustion efficiency of the combustion gas can be determined using the selected model, the second net heating value, and selected ones of the process conditions and the environmental conditions. Total emissions of the combustion mixture can be further determined from the combustion efficiency and a volumetric flow rate of the combustion gas.

Abstract: A method includes receiving a gas mixture at a first pressure including at least a primary gas and a secondary gas and changing a pressure of the received gas mixture from the first pressure to a second pressure. Further, the method includes determining a spectra of the gas mixture at the second pressure, wherein at least the first spectral line of the primary gas is spectrally distinguished from at least the second spectral line of the secondary gas, identifying a peak wavelength associated with the spectrally distinguished first spectral line of the primary gas based on at least two wavelengths of the secondary gas corresponding to at least two peak amplitudes in the spectra of the gas mixture, and determining a concentration of the primary gas based on the identified peak wavelength associated with the spectrally distinguished first spectral line of the primary gas.

Abstract: A method includes receiving a gas mixture at a first pressure including at least a primary gas and a secondary gas and changing a pressure of the received gas mixture from the first pressure to a second pressure. Further, the method includes determining a spectra of the gas mixture at the second pressure, wherein at least the first spectral line of the primary gas is spectrally distinguished from at least the second spectral line of the secondary gas, identifying a peak wavelength associated with the spectrally distinguished first spectral line of the primary gas based on at least two wavelengths of the secondary gas corresponding to at least two peak amplitudes in the spectra of the gas mixture, and determining a concentration of the primary gas based on the identified peak wavelength associated with the spectrally distinguished first spectral line of the primary gas.

Abstract: A system includes a moisture analyzer configured to detect moisture in a process gas. The moisture analyzer includes an absorption cell that encloses and conducts the process gas. The moisture analyzer also includes a pressure control device that may reduce a pressure of the process gas inside the absorption cell. The moisture analyzer includes a light emitting device that may transmit light through the process gas inside the absorption cell, as well as a photodetector that may detect an intensity of the light transmitted through the process gas and exiting the absorption cell.

Abstract: A system includes a moisture analyzer configured to detect moisture in a process gas. The moisture analyzer includes an absorption cell that encloses and conducts the process gas. The moisture analyzer also includes a pressure control device that may reduce a pressure of the process gas inside the absorption cell. The moisture analyzer includes a light emitting device that may transmit light through the process gas inside the absorption cell, as well as a photodetector that may detect an intensity of the light transmitted through the process gas and exiting the absorption cell.

Abstract: A system includes a moisture analyzer configured to detect moisture in natural gas. The moisture analyzer includes an absorption cell that encloses and conducts the natural gas. The moisture analyzer also includes a pressure control device that may reduce a pressure of the natural gas inside the absorption cell. The moisture analyzer includes a light emitting device that may transmit light through the natural gas inside the absorption cell, as well as a photodetector that may detect an intensity of the light transmitted through the natural gas and exiting the absorption cell.

Abstract: A system includes a moisture analyzer configured to detect moisture in natural gas. The moisture analyzer includes an absorption cell that encloses and conducts the natural gas. The moisture analyzer also includes a pressure control device that may reduce a pressure of the natural gas inside the absorption cell. The moisture analyzer includes a light emitting device that may transmit light through the natural gas inside the absorption cell, as well as a photodetector that may detect an intensity of the light transmitted through the natural gas and exiting the absorption cell.

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.

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.

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.

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.

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.

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.

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.

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.

Abstract: A flow meter is powered by a loop power supply which supplies a supply voltage. A load is powered by a load voltage and includes at least a processor for calculating a flow rate, an ultrasonic transducer power circuit, and an ultrasonic transducer receiving circuit. A power regulating circuit is disposed between the loop power supply and the load. The power regulating circuit includes a power converter responsive to the supply voltage to vary the load voltage in response to a control signal, a safe storage device between the converter and the load for storing power when not needed by the load and for delivering power to the load when required by the load, and a control subsystem for providing the control signal to the converter based on the setting of the loop power supply by the load. A power management subsystem is configured to detect the load voltage and to reduce the power consumption of the load at one or more predetermined set points.