Abstract:
A flexible gas sensor includes a housing with a predetermined form factor, a photoacoustic gas sensing chamber, and at least one of acoustic, temperature, relative humidity or pressure sensors in combination with processing circuitry which can emulate the characteristic gas response output of a catalytic bead pellistor-type gas sensor in response to a selected gas. The processing circuitry can include a programmable processor and a storage unit. The storage unit can be loaded with data and executable instructions to specify, at least in part, how the signals from the photoacoustic sensor are to be processed by the processing circuitry.
Abstract:
A method of using a spectrometer (1) to produce corrected diamond Attenuated Total Reflectance (ATR) spectral data. The method comprises the steps of: acquiring, using the spectrometer (1), an initial set of ATR spectral data for a sample (8) pressed into contact with a diamond ATR crystals; numerically matching, using the spectrometer (1), a pressure dependent diamond artefact reference spectrum to a corresponding pressure dependent diamond artefact in the initial set of ATR spectral data; and numerically subtracting out the numerically matched pressure dependent diamond artefact reference spectrum from the initial set of ATR spectral data to yield a corrected set of ATR spectral data for the sample for output by the spectrometer.
Abstract:
An apparatus for detecting a concentration of a trace target gas in a sample gas comprises a light source (110), for example a tunable diode laser, for emitting light at a wavelength corresponding to an absorption line of the target gas and means (105) operatively connected to said light source for modulating the wavelength of the emitted light, a detector (125) positioned to detect the intensity of light emitted from the light source that has passed through the sample gas at a multiple of the modulation frequency of the light source, for example second harmonic detection, a pressure sensor (120) for detecting the pressure of the sample gas, and a control unit (135) coupled to the detector, the pressure sensor, and the light source, said control unit being arranged to adjust the modulation amplitude' of the light source based on the detected pressure.
Abstract:
A system includes a light source, a detector, at least one pressure sensor, and a control unit. The light source emits light at a wavelength substantially corresponding to an absorption line of a target gas. The detector is positioned to detect the intensity of light emitted from the light source that has passed through the target gas. The pressure sensor detects the pressure of the target gas. The control circuit is coupled to the detector and the light source to adjust the modulation amplitude of the light source based on the pressure detected by the at least one pressure sensor. Related systems, apparatus, methods, and/or articles are also described.
Abstract:
L'invention propose un procédé et un dispositif de détection d'espèces gazeuses minoritaires dans un mélange par spectroscopie d'émission optique au moyen d'un spectromètre optique (8), dans lequel on utilise la radiation émise par un plasma (4) présent dans le mélange gazeux à analyser, et on retient, dans le spectre de cette radiation, les raies d'une espèce gazeuse majoritaire dont l'amplitude est sensible à la présence de l'espèce minoritaire, et on déduit de l'amplitude de cette ou de ces raies sensibles une information sur la concentration de l'espèce gazeuse minoritaire. Il est alors possible d'assurer une surveillance d'espèces gazeuses minoritaires en temps réel.
Abstract:
PROBLEM TO BE SOLVED: To certainly, rapidly and inexpensively obtain the index related to the concentration value and the change of the type of gas present in small amount and difficult to excite in a gas mixture to be investigated, without using expensive and bulky machineries which are difficult to operate. SOLUTION: In the method for detecting the type of a small amount of the gas in a mixture by emission spectroscopy using an optical spectrometer, and an apparatus therefor, the light emitted from the plasma 4 present in the gaseous mixture to be analyzed is used and, in the spectrum of light, the line of the amount of a large amount of the gas showing the amplitude responding line is discriminated for estimating the data related to the concentration of a small amount of the gas, is estimated from the amplitude of the response line. By using this constitution, the kind of a small amount of the gas is monitored in a real time. COPYRIGHT: (C)2005,JPO&NCIPI