Abstract: A system for measuring a target gas via laser absorption spectroscopy in an open-air configuration, comprising a mid-infrared distributed feedback interband cascade laser (mid-IR DFB-ICL) having a wavelength selected to correspond with a spectral absorption line of the target gas and first electronic circuitry to control the laser temperature, current and modulation frequency. The mid-IR DFB-ICL is mounted to a heat sink. The system includes an optical component that projects a beam of the mid-IR DFB-ICL onto a distal backscattering directionally-reflective target and an optical receiver assembly that receives a fraction of the laser light that is backscattered from the directionally-reflective target and focuses the collected light onto an uncooled photodetector having a spectral bandwidth and optical configuration selected to optimize signal-to-noise response to received laser light.

Abstract: Systems and method for analysing contaminants of a gas sample of natural gas are provided. An interrogation light beam propagates into a chamber of a multipass gas cell receiving the gas sample. The interrogation light beam has a wavelength controlled to alternately correspond to an absorption wavelength of H2S and an absorption wavelength of an additional gas contaminant. The additional gas contaminant may for example be CO2 or H2O. In some implementation, a single laser emitter may be used to generate the interrogation light beam at the H2S and CO2 wavelengths. In some implementations, two different laser emitters may be used to generate the interrogation light beam at the H2S and H2O wavelengths. A WMS detection scheme may be used.

Abstract: Systems and method for analysing contaminants of a gas sample of natural gas are provided. An interrogation light beam propagates into a chamber of a multipass gas cell receiving the gas sample. The interrogation light beam has a wavelength controlled to alternately correspond to an absorption wavelength of H2S and an absorption wavelength of an additional gas contaminant. The additional gas contaminant may for example be CO2 or H2O. In some implementation, a single laser emitter may be used to generate the interrogation light beam at the H2S and CO2 wavelengths. In some implementations, two different laser emitters may be used to generate the interrogation light beam at the H2S and H2O wavelengths. A WMS detection scheme may be used.

Abstract: An apparatus and method for monitoring gas velocity, temperature, and pressure in combustion systems and flow devices, in particular at inlets and isolators of scramjet engines. The invention employs wavelength modulation spectroscopy with first harmonic detection and without the need to scan the full absorption spectra.

Abstract: An apparatus and method for monitoring oxygen concentrations in fuel tank ullage comprising providing a sensor head comprising an optical cavity, exposing the optical cavity to an ambient gaseous environment of a fuel tank or air separation module, via a laser light source emitting wavelength modulated light through the cavity, and receiving the wavelength modulated light with a detector.

Abstract: An apparatus for and method of detecting fires comprising detecting (with one or more detectors) levels of carbon monoxide, carbon dioxide, and smoke in an ambient environment, computing (using a processor) over time rates of increase of each of the levels, and generating an alarm if one or more of the rates of increase exceed predetermined threshold rates of increase.

Abstract: An apparatus and method for monitoring oxygen concentrations in fuel tank ullage comprising providing a sensor head comprising an optical cavity, exposing the optical cavity to an ambient gaseous environment of a fuel tank or air separation module, via a laser light source emitting wavelength modulated light through the cavity, and receiving the wavelength modulated light with a detector.

Abstract: An apparatus for and method of detecting fires comprising detecting (with one or more detectors) levels of carbon monoxide, carbon dioxide, and smoke in an ambient environment, computing (using a processor) over time rates of increase of each of the levels, and generating an alarm if one or more of the rates of increase exceed predetermined threshold rates of increase.