Abstract: Components resolved in time by a separator accumulate in a sample cell and are analyzed by electromagnetic radiation-based spectroscopic techniques. The sample cell can be configured for multiple path absorption and can be heated. The separator can be a gas chromatograph or another suitable device, for example a distillation-based separator. The method and system described herein can include other mechanical elements, controls, procedures for handling background and sample data, protocols for species identification and/or quantification, automation, computer interfaces, algorithms, software or other features.

Abstract: Exhaust from an NG fired stationary or non-stationary RICE, such as, for example, a lean burn RICE, is directed to a first oxidation catalyst, then to a second oxidation catalyst. The second oxidation catalyst is operated at a temperature higher than a minimum temperature required to oxidize formaldehyde (to CO2 and H2O) and lower than a minimum temperature required to form formaldehyde, e.g., from CH4 and O2.

Abstract: Indoor air is purified using a purifying solution in an arrangement capable of removing formaldehyde and other pollutants, such as, for example, particulates. The arrangement can prevent re-vaporization of volatile compounds and can generate air that has been humidified or dehumidified. In one approach, incoming air is contacted with the purifying solution in a packed bed.

Abstract: A method is provided for monitoring one or more silicon-containing compounds present in a biogas. The method includes generating a first absorption spectrum based on a ratio of a first spectral measurement and a second spectral measurement. The first spectral measurement is from a non-absorptive gas having substantially no infrared absorptions in a specified wavelength range of interest and the second spectral measurement is from a sample gas comprising the biogas. The method includes generating at least one surrogate absorption spectrum based on, at least, individual absorption spectrum for each of a subset of one or more silicon-containing compounds selected from a larger set of known silicon-containing compounds with known concentrations. A total concentration of the one or more silicon-containing compounds in the biogas can be calculated based on the first absorption spectrum and the at least one surrogate absorption spectrum.

Abstract: A method for monitoring of siloxane compounds in a biogas includes the step of generating a first absorption spectrum based on a ratio of a first spectral measurement and a second spectral measurement. The first spectral measurement is from a non-absorptive gas having substantially no infrared absorptions in a specified wavelength range of interest and the second spectral measurement is from a sample gas comprising the biogas. The method also includes the step of calculating a concentration of at least one siloxane compound in the biogas using a second absorption spectrum based on, at least, a first individual absorption spectrum for a known concentration of the at least one siloxane compound.

Abstract: A method for monitoring of siloxane compounds in a biogas includes the step of generating a first absorption spectrum based on a ratio of a first spectral measurement and a second spectral measurement. The first spectral measurement is from a non-absorptive gas having substantially no infrared absorptions in a specified wavelength range of interest and the second spectral measurement is from a sample gas comprising the biogas. The method also includes the step of calculating a concentration of at least one siloxane compound in the biogas using a second absorption spectrum based on, at least, a first individual absorption spectrum for a known concentration of the at least one siloxane compound.

Abstract: A spectroscopic detection system is described for monitoring ambient air for toxic chemical substances. The system can be a compact, portable multiple gas analyzer capable of detecting and discriminating a broad range of chemical constituents including various nerve and blister agents as well as toxic industrial chemicals at low or sub part per billion (ppb) levels. The system minimizes false alarms (e.g., false positives or negatives), features high specificity, and can operate with response times on the order of a few seconds to a few minutes, depending on the application. The system can be an entirely self-contained analyzer, with a Fourier Transform Infrared (FTIR) spectrometer, a gas sample cell, a detector, an embedded processor, a display, power supplies, an air pump, heating elements, and other components onboard the unit with an air intake to collect a sample and an electronic communications port to interface with external devices.

Abstract: A spectroscopic detection system is described for monitoring ambient air for toxic chemical substances. The system can be a compact, portable multiple gas analyzer capable of detecting and discriminating a broad range of chemical constituents including various nerve and blister agents as well as toxic industrial chemicals at low or sub part per billion (ppb) levels. The system minimizes false alarms (e.g., false positives or negatives), features high specificity, and can operate with response times on the order of a few seconds to a few minutes, depending on the application. The system can be an entirely self-contained analyzer, with a Fourier Transform Infrared (FTIR) spectrometer, a gas sample cell, a detector, an embedded processor, a display, power supplies, an air pump, heating elements, and other components onboard the unit with an air intake to collect a sample and an electronic communications port to interface with external devices.

Abstract: A spectroscopic detection system is described for monitoring ambient air for toxic chemical substances. The system can be a compact, portable multiple gas analyzer capable of detecting and discriminating a broad range of chemical constituents including various nerve and blister agents as well as toxic industrial chemicals at low or sub part per billion (ppb) levels. The system minimizes false alarms (e.g., false positives or negatives), features high specificity, and can operate with response times on the order of a few seconds to a few minutes, depending on the application. The system can be an entirely self-contained analyzer, with a Fourier Transform Infrared (FTIR) spectrometer, a gas sample cell, a detector, an embedded processor, a display, power supplies, an air pump, heating elements, and other components onboard the unit with an air intake to collect a sample and an electronic communications port to interface with external devices.

Abstract: A spectroscopic detection system is described for monitoring ambient air for toxic chemical substances. The system can be a compact, portable multiple gas analyzer capable of detecting and discriminating a broad range of chemical constituents including various nerve and blister agents as well as toxic industrial chemicals at low or sub part per billion (ppb) levels. The system minimizes false alarms (e.g., false positives or negatives), features high specificity, and can operate with response times on the order of a few seconds to a few minutes, depending on the application. The system can be an entirely self-contained analyzer, with a Fourier Transform Infrared (FTIR) spectrometer, a gas sample cell, a detector, an embedded processor, a display, power supplies, an air pump, heating elements, and other components onboard the unit with an air intake to collect a sample and an electronic communications port to interface with external devices.

Abstract: A fault detection and classification system for wafer etching, tool cleaning, and other fabrication processes employs exhaust gas composition data from a Fourier transform infrared spectrometer in addition to machine-state and other process-state data. Process control may be initiated based upon the classification of a fault.