Abstract: A fire detector with a passive CO2 sensor generates a detector signal based upon a 15? absorption band of CO2 and a signal processor generates an alarm signal when a preselected criterion is met. The passive CO2 sensor has a passive infrared source with a source temperature, a waveguide sample chamber with a gas medium temperature (which is less than the source temperature), a heat exchanger (that reduces the temperature of CO2 gas as it passes into the waveguide sample chamber and may be thermally coupled to the sample chamber) and an infrared detector assembly with a detector temperature (which is less than the source temperature). An exterior surface of the passive infrared source has a high emissivity while the detector assembly and the sample chamber (which can be thermally coupled to each other but not the passive infrared source) have a low emissivity.

Abstract: The gas detector device comprises at least a VCSEL source and at least a light sensor for detecting a light beam having passed through a sample chamber containing a given gas to be detected. The detection signal of the sensor directly provided to or is time derivated by an electronic derivator and then provided to respective lock-in amplifiers in order to generate a two different 2f-detection, f being the frequency of a wavelength modulation of the source, and thus to provide two corresponding measuring signals the division of which gives a precise value of the gas concentration. The invention uses at least a first modulation reference signal at twice and a second modulation reference signal at twice of the modulation frequency of the laser source.

Abstract: A fire detector and method for detecting fires uses a passive NDIR sensor that generates a detector signal based upon either a 15? absorption band of CO2 or a 6.27? absorption band of H2O and a signal processor which receives the detector signal and generates an alarm signal when a preselected criterion is met. The NDIR sensor relies upon a passive infrared source (such as a very thin film of black plastic material) with a high emissivity (e.g., approximately 1.0), a sample chamber with a low emissivity (e.g., approximately 0.03) thermally decoupled from the passive infrared source and an infrared detector located in a detector assembly thermally coupled to the sample chamber while a heat exchanger is thermally coupled to the sample chamber.

Abstract: A gas sensor arrangement for detecting the presence or concentration of an analyte in a measuring gas comprises a gas measuring chamber having an inlet for receiving the measuring gas. A measuring radiation source is arranged in the gas measuring chamber. The measuring radiation source emits radiation in a non-uniform pulse sequence according to a signal from a controller. A radiation detector receives the radiation emitted from the measuring radiation source. The radiation detector sends an output signal to the controller for processing.

Abstract: A condensation sensor detects whether hydrogen peroxide gas has condensed in a sealed space and determines the condition of a condensate film upon passage of time. The condensate film in the sealed space is controlled with the condensation sensor. The condensation sensor includes a condensate forming part with a plurality of glass plates arranged so that a direction of irradiation is substantially perpendicular to a surface direction, and the condensate forming part is disposed between a projector and a light receiver. The condensation sensor is placed inside an isolator and irradiated with laser beams. The condensate film formed on the glass plates is detected from a change in the quantity of light received by the light receiver, thus the condition of condensation on the surface of an item to be sterilized inside the isolator is presumed, and accordingly, the necessary and sufficient amount of gas introduced is determined.

Abstract: A vaporizer (14) supplies hydrogen peroxide and water vapor to a high level disinfection or sterilization region (20). Mid-infrared light detectors (32) detect light in the mid-infrared range which has traversed a region of the treatment chamber in a first narrow spectrum centered at 8,000 nanometers which is absorbed by the hydrogen peroxide vapor, a second narrow spectrum which is absorbed by the water vapor, and a third spectrum that is absorbed by neither the hydrogen peroxide vapor nor the water vapor. From these measurements, an absorbance or transmittance is determined (40) from which the concentrations of hydrogen peroxide and water vapor are determined (42). Monitored temperature (44) and the determined concentrations are converted into a percent saturation (54). The supply of hydrogen peroxide and water vapor to the chamber is controlled (60) in accordance with the determined percent saturation.

Abstract: A remote sensing device for determining at least one characteristic of a vehicle emission plume includes a radiation source, a detector, and a plurality of filters. Either the filters or the detector are movable relative to the other such that different filters, each of which is capable of filtering out radiation except radiation of a predetermined wavelength band, can be used to filter the radiation directed to the detector. Also disclosed is a method for remotely determining at least one characteristic of a vehicle emission plume using a single detector and a plurality of filters wherein either the detector or the filters are positionable relative to one another.

Abstract: An evolved gas analysis system contains a first measurement step of heating a first sample containing measurement target material and non-measurement target material at a predetermined temperature programming rate and detecting the amount of gas evolved from the first sample; a second measurement step of heating a second sample achieved by excluding the measurement target material from the first sample at the same temperature increasing rate as the first measurement step, and detecting the amount of gas evolved from the second sample; and a correcting step of calculating the amount of gas evolved from the measurement target material on the basis of the detected data of the respective steps.

Abstract: A non-dispersive infrared measuring arrangement for a multigas analyzer is described having a radiation source (10), a measuring chamber (20), a beam splitter (3), at least a first and a second detector unit (21, 22) both with at least two detectors (1a, 1b; 2a, 2b); and optical filters in radiation beam portions ending in said detectors. The detector units receive the reflected beam portions (RR) and the transmitted beam portion (RT). Both the first and second detector units (21, 22) have: at least one measuring detectors (1a, 1b) provided with an optical measurement filter (5a, 5b); and at least one reference detectors (2a, 2b) provided with an optical reference filter (6a, 6b). Alternatively, the first detector unit (21) has at least two measuring detectors (1a, 1b) each provided with an optical measurement filter (5a, 5b), and the second detector unit (22) has at least two reference detectors (2a, 2b) each provided with an optical reference filter (6a, 6b).

Abstract: A system and method are disclosed for the detection of water vapor in a natural gas background. The system includes a light source operating in a wavelength range such as, 1.877–1.901 ?m, 2.711–2.786 ?m, or 920–960 nm, passes through the natural gas to be detected by a detector. In one embodiment, the light source is a tunable diode laser and the moisture level is determined by harmonic spectroscopy. In other embodiments, a VCSEL laser is utilized.

Abstract: A gas detector that includes at least one source of infrared radiation, at least two analytical detectors, each analytical detector adapted to provide an output signal indicative of a first gas of interest and positioned to receive radiation from the source of radiation, at least one reference detector adapted to receive radiation of a predetermined wavelength, a sample chamber for receiving a gaseous sample, and an optical path length disposed between the source of radiation and the analytical detectors and passing through the sample chamber.

Abstract: A method for determining the safety of a gas mixture containing first and second flammable components together with non-flammable components, comprises using an optical detector to make at least two measurements influenced by the concentration in the gas mixture of the first and second flammable components. The percentage lower explosion limit of the gas mixture is calculated by a method based on the combination of the measurements. The method leads to acceptably accurate results, despite the presence of other flammable component(s) in the gas mixture.

Abstract: A blackbody radiation device (110) includes a planar filament emission element (102) and a planar detector (104) for respectively producing and detecting radiation having width dl/1 less than about 0.1 to test a sample gas, where 1 is the wavelength of the radiation; a reflector (108); a window (W); an electrical control (118); and a data output element (116).

Abstract: A lightweight and portable analyzer is provided. At least one component of the analyzer is made from a lightweight material, such as ABS. A manifold can have a plate and gas passages ultrasonically welded together. By having at least one component made from a lightweight material, the analyzer is lighter.

Abstract: A method and apparatus for real-time monitoring of the substrate and the gaseous process environment in a semi-conductor process step is described. The method uses infrared spectroscopy for in-situ analysis of gaseous molecular species in the process region and characterization of adsorbed chemical species on a substrate. The process monitoring can be applied to endpoint- and fault detection in etching and deposition processes, in addition to chamber cleaning and chamber condition steps.

Abstract: Device of modular construction which permits the simultaneous or not-simultaneous recording and characterization of solid and liquid particles and gaseous components of engine exhaust gases on various test supports, with only small or no modification of the test support. Methods are based on individual or combined usage of laser scattering techniques, laser-induced breakdown spectroscopy, laser-induced ionization spectroscopy, laser-induced atomic fluorescence spectroscopy, IR-/VIS-/UV-laser absorption spectroscopy and laser-induced incandescence. Use of individual or combined usage of such devices permits the analysis of raw exhaust gas, the conditioned and/or treated exhaust gases for monitoring and checking working pattern of engine, individual components of exhaust gas treatment and/or total system on test beds and on vehicle and can be used for control of motor and/or exhaust components, such as catalysts and particle filters, on test beds and in driven usage, e.g.

Abstract: A multi-component analyzing apparatus in which infrared light is irradiated to a measuring-subject sample S which is constituted by either measuring-subject components whose sorts or quantities are limited or by a mixed article made of said measuring-subject components; intensity of infrared light having respective wavelength ranges which are fitted to infrared absorption spectra of the respective measuring-subject components among such infrared light penetrated through the measuring-subject sample S is measured by employing a plurality of detectors 4a to 4g corresponding thereto; and said multi-component analyzing apparatus is comprised of a calculation processing unit 6 for analyzing the infrared light intensity of the respective wavelength ranges so as to acquire concentration x1 to x7 of the respective measuring-subject components; wherein the calculation processing unit 6 is capable of executing an analyzing process program P for executing analysis operations of the concentration x1 to x7 of the respecti

Abstract: An infrared absorption measurement method including: (a) measuring infrared absorption of a target component in a sample gas while decompressing the sample gas so that an absorption area in a peak region of the target component in the infrared absorption shown in a graph is within a predetermined range, the graph showing the relationship between the wave number and absorbance of the sample gas; and (b) calculating the concentration of the target component in the sample gas based on the absorption area and pressure of the decompressed sample gas.

Abstract: An infrared absorption measurement method includes: (a) measuring infrared absorption of a measurement target component in a state in which a sample gas including the measurement target component is decompressed; (b) calculating an absorption area in a peak region of the measurement target component in the infrared absorption shown in a graph which shows the relationship between the wave number and absorbance of the sample gas; and (c) calculating a concentration of the measurement target component in the sample gas based on the absorption area and pressure of the sample gas during decompression.

Abstract: A gas sensor, which could be a sensor of combustible gases, incorporates a diffusion chamber having symmetrical sensing and reference portions. A common source emits infrared-type radiant energy symmetrically into the two portions. Each portion incorporates a curved reflective surface which reflects incident infrared onto a respective sensor. Each sensor has a filter which passes a different selected band of energy. A fluid, such as gas being sensed, passes laterally through the chamber.

Abstract: A method and apparatus for monitoring the flue gases of a furnace combustion process is disclosed. A by-pass circuit that communicates a sample of flue gases to be monitored from a furnace, through a measurement chamber and back to the furnace or furnace exhaust duct is provided. The by-pass circuit has a gas sampling probe with a fume inlet opening, the probe being positioned for withdrawing the sample to be monitored and transmitting it through the by-pass circuit. A measurement device is positioned in the measurement chamber and comprises an in situ optical device which provides real-time measurement of targeted flue gas species concentrations.

Abstract: An apparatus and method for simultaneous detection of N gas species through laser radiation attenuation techniques is disclosed. Each of the N species has a spectral absorption band. N laser sources operate at a wavelength ?N in a spectral absorption band separated by the cutoff wavelength for single-mode transmission. Each laser source corresponds to a gas species and transmits radiation through an optical fiber constructed and arranged to provide single-mode transmission with minimal power loss.

Abstract: The invention relates to a radiation detector, an arrangement and a method for an energy-dispersive detection of X-ray photons. X-ray photons are allowed to collide (701) in the radiation detector (201, 601), whereby there are produced (702, 703, 704, 705, 706, 707, 708) observations of the X-ray photons that collided in the detector. According to the invention, there are separately produced observations of X-ray photons (702, 703, 704) that collided in the first detector space (205, 501) of the radiation detector and X-ray photons (705, 706, 707, 708) that collided in the second detector space (206, 502) of the radiation detector. The (712) observations of X-ray photons that collided in the first detector space (205, 501) are ignored, when there is received a simultaneous observation of an X-ray photon that collided in the second detector space.

Abstract: In an isotopic gas analyzer, a gas injector (21) is provided for pressurizing a gas specimen in cells (11a,11b). The pressurization of the gas specimen virtually produces the same effect as increasing the concentration of carbon dioxide in the gas specimen, thereby improving an S/N ratio for the analysis and hence data reproducibility.

Abstract: A method and apparatus are provided for in situ monitoring and analyzing of process parameters for semiconductor fabrication processes including cleaning semiconductor wafers utilizing a supercritical fluid or a high pressure liquid such as CO2. The method and apparatus utilize a spectrometer having a reflective mirror proximate the vessel holding the high pressure fluid. NIR radiation transmitted into the vessel through a window and out of the vessel through an opposed window is reflected and detected and measured and the composition of the fluid in the pressure vessel is determined allowing the user to control process parameters based on the measured composition.

Abstract: A new type of mounting mechanism for a light detector that cools the mounting for a light detector such that the maximum efficiency of the light detector's internal cooler can be achieved despite an elevated enclosure temperature, leading to more stable measurements of light from the detector. This same mounting provides thermal isolation from a baseplate, to which other optical path components are attached.

Abstract: Method and apparatus for providing real-time data indicative of the isotopic composition of formation fluids during drilling. The method includes the steps of: (a) providing a reference fluid having a known isotopic composition in a reference cell; (b) capturing a sample of formation; (c) providing at least one laser beam; (e) passing a beam through the reference fluid, measuring the reference-measurement beam before and after it passes through the reference fluid; (f) and passing a beam through the sample, measuring the beam before and after it passes through the sample, and calculating a first isotope concentration from those measurements. The measurements can provide information relating to the carbon isotopic composition of individual compounds in hydrocarbon gas mixtures, with the individual compounds including methane, ethane, propane, iso- or normal butane, or iso- or normal pentane.

Abstract: A sterilization system (14) includes a sensor (10) for detection of a component, such as hydrogen peroxide vapor, in a multi-component vapor, such as a mixture of vapor hydrogen peroxide and water supplied to a chamber (12) of the system. The sensor preferably uses a wavelength range in which hydrogen peroxide strongly absorbs but other components of the vapor, such as water, do not. A suitable wavelength for detection of hydrogen peroxide is from about 7500 to about 8400 nm, since there is little absorption by water in this range. This avoids the need to use complex subtraction procedures normally used to remove the contribution of water from detected absorbance measurements. A control system (16, 30) controls operating conditions of the sterilization system, such as a heater (82), pressure release valves (74), vaporization rate of hydrogen peroxide by a vaporizer (22), and the like to maintain optimum sterilization conditions within the chamber.

Abstract: A portable spectrophotometric system for detecting one or more target substances. In a representative embodiment, a system of the invention has an optical grating, an array of photo-detectors, and a MEMS device having a movable plate positioned between the grating and the array. Light transmitted through a gaseous sample is dispersed by the grating and is imaged onto the movable plate, which has a plurality of openings corresponding to selected infrared absorption lines of the target substance. A small-amplitude oscillation is imparted onto the plate such that the openings periodically move in and out of alignment with the corresponding intensity features in the image, which modulates electrical signals generated by the corresponding photo-detectors. A lock-in signal processor analyzes the modulation pattern by comparing it to the pattern expected in the presence of the target substance.

Abstract: The invention relates to a method and an apparatus for non-dispersive analysis of gas mixtures for determining the concentration of such a first gas component in a gas mixture, whose absorbance may be influenced by other gas components of said gas mixture. The apparatus comprises a sample chamber (2) for containing the gas mixture, a radiation source (1) for transmitting radiation through the gas mixture, a first optical transmission band filter (5) with a first absorption transmission band of the first gas and a first radiation detector (4). The apparatus further comprises a second optical transmission band filter (8) with a second transmission band, which is outside the first transmission band, and a second detector (7). The concentration determining means (23) are arranged to determine the concentration of the first gas using a certain formula or formulas and using the detected intensities.

Abstract: An optical system for a gas component analysis includes an emitter for emitting first light beam having a first spectrum, a second emitter for emitting a second light beam at a second spectrum, a first receiver for receiving the first light beam, and a second receiver for receiving the second light beam.

Abstract: Methods and apparatus for the analysis of exhaled breath by spectroscopy are disclosed. An optical cavity containing the exhaled breath, typically comprising a pair of opposing high reflectivity mirrors, is used to implement a cavity enhanced absorbtion technique. Pairs of 12CO2 and 13CO2 absorbtion lines suitable for use in spectroscopic breath analysis are also disclosed.

Abstract: An infrared absorption measurement method includes: (a) measuring infrared absorption of a measurement target component in a state in which a sample gas including the measurement target component is decompressed; (b) calculating an absorption area in a peak region of the measurement target component in the infrared absorption shown in a graph which shows the relationship between the wave number and absorbance of the sample gas; and (c) calculating a concentration of the measurement target component in the sample gas based on the absorption area and pressure of the sample gas during decompression.

Abstract: A method for quantitative imaging of gas emissions utilizing optical techniques combining gas correlation techniques with thermal background radiation or gas self-emission radiation is presented. A simultaneous recording of images with and without filtering through a gas-filled cell is utilized for the identification of a selected gas. A new calibration method provides the display of the integrated gas concentration spatially resolved in the generated final image. The procedure includes methods for a correct subtraction of the zero level, consisting of self-radiation from the dual-image camera device including the as correlation cell and electronic offset, and for the calculation of the specific absorption as a function of the difference temperature between the background and the gas emission.

Abstract: A method for identification and partial-pressure determination of two gases in an unknown anesthesia gas mixture comprising n possible gases by measuring the infrared optical radiation, transmitted through the gas mixture, that passes through m filters having different transmission wavelength ranges, in which n is a number greater than 2 and m is a number less than n. The method evaluates the exit intensities, measured after passage through the filters, of the infrared optical radiation transmitted through the unknown gas mixture in such a way that with three filters, for instance, two gases in an unknown gas mixture comprising five possible gases can be identified, and their partial pressures can be determined. By dividing the partial pressures by the total pressure, it is optionally also possible to determine the concentration of the gases.

Abstract: The present invention provides a spectroscopic method for analyzing isotopes which makes it possible to simplify a system for measurement and to identify isotopes with high accuracy and sensitivity and to carry out quantitative analysis. The spectroscopic method for analyzing isotopes uses a semiconductor laser beam having as a wavelength zone a 2000 nm-wavelength band as a beam source of wavelengths of the absorption spectra of the isotopes. A reference gas is used for identification of the isotopes where the gas contains collating components having two wavelengths (W1, W2) of well-known absorption spectra in wavelength bands close to the wavelengths (w1, w2) of the absorption spectra of the isotopes.

Abstract: Methods are disclosed for determining the monotonic functional relationship between (A) the integrated absorbance of spectral energy within a spectral region of interest of an analyte (i) that decomposes during the time experimental spectral data for determining the relationship are being obtained, or (ii) whose spectral data are pressure sensitive at pressures below a given pressure, or (iii) that decomposes during the time the spectral data are being obtained and whose spectral data are pressure sensitive and (B) the concentration of the analyte before decomposition commences. Methods are also disclosed for using the monotonic functional relationship to determine the concentration of the analyte in an unknown from the integrated absorbance of spectral energy within the spectral region of interest for the unknown.

Abstract: The present invention describes a unique method and apparatus for applying near-infrared spectroscopy to estimate weight percent of methane in crude oil from which one can then infer gas-oil ratio (GOR) of crude oils downhole in real time while collecting a fluid sample. The correlation equations provided by this invention use two wavelengths, one centered at 1670 and the other centered at 1682 nm. Both wavelengths are primarily sensitive to the methane peak absorption. To significantly improve the fit, non-spectroscopic parameters, such as temperature or pressure, can be included in the correlation equation. Also, this invention can be used to monitor sample cleanup by monitoring the increase in GOR associated with cleanup as a fluid being pumped from the formation transitions from mostly gas-free filtrate to mostly gas-containing crude oil.

Abstract: An improved light source for use in an opacity monitor (transmissometer) that reduces the variation in light intensity across a projected light beam to enable a more accurate and stable method for measuring the opacity of gases in a stack/duct, especially at low values (e.g., <10%) of opacity while operating within specific performance requirements.

Abstract: The present invention resides in an infrared identification system for identifying military vehicles as friendly or hostile. The infrared identification system includes a seed introduction system, in each friendly vehicle, that introduces trace quantities of a particular seed formulation into the vehicle's exhaust. An infrared detection system, also in each friendly vehicle, detects the spectrally-discrete thermal emissions of the seed formulation to identify those vehicles having the thermal emissions as friendly. The infrared identification system provides rapid and positive friend or foe identification of land, sea and air vehicles at long ranges without being jammed, intercepted or mimicked.

Abstract: A multi-component analyzing apparatus in which infrared light is irradiated to a measuring-subject sample S which is constituted by either measuring-subject components whose sorts or quantities are limited or by a mixed article made of said measuring-subject components; intensity of infrared light having respective wavelength ranges which are fitted to infrared absorption spectra of the respective measuring-subject components among such infrared light penetrated through the measuring-subject sample S is measured by employing a plurality of detectors 4a to 4g corresponding thereto; and said multi-component analyzing apparatus is comprised of a calculation processing unit 6 for analyzing the infrared light intensity of the respective wavelength ranges so as to acquire concentration x1 to x7 of the respective measuring-subject components; wherein the calculation processing unit 6 is capable of executing an analyzing process program P for executing analysis operations of the concentration x1 to x7 of the respecti

Abstract: A method and apparatus are provided for in situ monitoring and analyzing of process parameters for semiconductor fabrication processes including cleaning semiconductor wafers utilizing a supercritical fluid or a high pressure liquid such as CO2. The method and apparatus utilize a spectrometer having a reflective mirror proximate the vessel holding the high pressure fluid. NIR radiation transmitted into the vessel through a window and out of the vessel through an opposed window is reflected and detected and measured and the composition of the fluid in the pressure vessel is determined allowing the user to control process parameters based on the measured composition.

Abstract: A gas component analysis system transmits, reflects, and detects light using infrared light source; a reflector unit; and a light detector. The light is transmitted through a gas, such as air containing vehicle emissions, reflected, and detected for analysis and measurement of the amount of absorption that has occurred at known wavelengths. The amount of absorption may be used to determine concentrations of reference gases corresponding to specific wavelengths.

Abstract: The invention relates to a method for detecting a test gas that may be present at a measuring location, using an infrared gas analyser (1) that comprises a cuvette (2), an infrared light source (3), an infrared detector (4), and two gas lines (15, 17). Said gas lines supply gases to the infrared gas analyser and one of said lines is adapted to take up a measuring gas at a measuring location that may contain a test gas. The second line (17) is adapted to take up gas from the surroundings of the measuring location (reference gas), which gas may contain a test gas background that is to be taken into consideration when detecting the test gas taken up at the measuring location. In order to improve the sensitivity of the analyser it comprises only one cuvette (2) and the measuring gas taken up at the measuring location and the reference gas are fed to the cuvette of the infrared gas analyser in such a manner that they are alternately present in the cuvette.

Abstract: A method for determining the safety of a gas mixture containing first and second flammable components together with non-flammable components, comprises using an optical detector to make at least two measurements influenced by the concentration in the gas mixture of the first and second flammable components. The percentage lower explosion limit of the gas mixture is calculated by a method based on the combination of the measurements. The method leads to acceptably accurate results, despite the presence of other flammable component(s) in the gas mixture.

Abstract: The invention includes a particle detection system that detects bioparticles in a sample utilizing a sensor device that receives photoacoustic signals from a sample. The invention includes a system for distinguishing biologically active particles from non-biologically active particles in a sample utilizing a transducer to receive a laser induced photoacoustic signal from the sample and a fluorescence detector to receive laser induced fluorescence. The invention includes a method of screening a sample for the presence of one or more particle types by subjecting a sample to laser light and measuring at least one photonic response and at least one acoustic response are measured from the sample to produce a sample composite data set which is compared to a signature data set from a control sample. The invention also includes methods for detecting a change in the particle composition within a test area.

Abstract: Method and apparatus for analyzing radiation using analyzers and encoders employing the spatial modulation of radiation dispersed by wavelength or imaged along a line.

Abstract: The invention relates to a method and an apparatus for non-dispersive analysis of gas mixtures for determining the concentration of such a first gas component in a gas mixture, whose absorbance may be influenced by other gas components of said gas mixture. The apparatus comprises a sample chamber (2) for containing the gas mixture, a radiation source (1) for transmitting radiation through the gas mixture, a first optical transmission band filter (5) with a first absorption transmission band of the first gas and a first radiation detector (4). The apparatus further comprises a second optical transmission band filter (8) with a second transmission band, which is outside the first transmission band, and a second detector (7). The concentration determining means (23) are arranged to determine the concentration of the first gas using a certain formula or formulas and using the detected intensities.

Abstract: One embodiment of the present invention is an analyzer of a multiplicity of gases in a sample gas that includes: (a) an infrared source of infrared radiation; (b) a multiplicity of band-pass filters, including a reference band-pass filter, and an opaque area; (c) a movement mechanism that places the band-pass filters and the opaque area in front of the infrared radiation at predetermined times, and includes a location pickup mechanism; (d) a location pickup mechanism detector that generates movement mechanism timer signals; (e) a sample cell disposed in a path of the infrared radiation through which the sample gas travels; (f) a gas temperature sensor and a pressure transducer that generate temperature and a pressure signals; (g) a detector that detects infrared radiation that has passed through the sample cell and generates detector signals; and (h) a controller that analyzes the movement mechanism timer signals, the detector signals, the temperature signal, and the pressure signal to provide concentrations

Abstract: A system and method are disclosed for the detection of water vapor in a natural gas background. The system includes a light source operating in the 1.877-1.901 &mgr;m wavelength range passes through the natural gas to be detected by a detector. In one embodiment, the light source is a tunable diode laser and the moisture level is determined by harmonic spectroscopy.