Abstract: A first, upper slotted disk (10) and a second, lower slotted disk (20) are arranged as a gas inlet (11) in a gas-measuring device (1). The first, upper slotted disk (10) and the second, lower slotted disk (20) are connected to one another and to a sensor housing (2) via a spacer element (29). The arrangement of the slotted disks (10, 20) in relation to one another is selected to be such that reduced propagation of light of an infrared radiation source (43) through both slotted disks (10, 20) into the measuring environment is achieved.

Abstract: Gas having stable isotopes is monitored continuously by using a system that sends a modulated laser beam to the gas and collects and transmits the light not absorbed by the gas to a detector. Gas from geological storage, or from the atmosphere can be monitored continuously without collecting samples and transporting them to a lab.

Abstract: This disclosure relates generally to a sampling device, and more particularly, a sampling device that facilitates spectroscopic measurements with a variable path length and the necessary software controlled algorithms and methods for such a device.

Abstract: Configurations herein include a novel process, system, etc., to measure a concentration of sulfur trioxide in a gas sample including sulfur trioxide, sulfur dioxide, and water. An example system can include an optical radiation source that generates an optical signal at a plurality of vibration-rotation transitions around at least one frequency selected from the group consisting of 1396.889 cm?1, 1396.908 cm?1, 1396.962 cm?1, 1397.003 cm?1, 1397.037 cm?1, 1397.047 cm?1, and 1397.052 cm?1. The optical signal is transmitted along an optical path through the gas sample. Based on adjusting a pressure of the gas sample, each of the plurality of vibration-rotation absorption transitions associated with the sulfur trioxide can be substantially isolated from interfering absorption by the sulfur dioxide and the water vapor in the gas sample. Based on a spectral analysis, the system generates a value indicative of a concentration of sulfur trioxide in the gas sample.

Abstract: Air-in-line sensor systems and methods of using same are provided. In a general embodiment, the present disclosure provides an adapter including first and second cylindrical portions defining a fluid flow channel, the first cylindrical portion comprising two adjacent wedge-shaped protrusions. Each wedge-shaped protrusion is infrared transmittive and defines an outer surface and an inner surface. In another embodiment, an air-in-line sensor device includes a tube and an infrared reflective sensor having an infrared light emitter and an infrared light detector. The infrared light emitter and the infrared light detector are positioned at or near an adapter so that an infrared light can be transmitted to the adapter and at least a portion of the infrared light reflected off the adapter can be detected by the infrared light detector.

Abstract: An optical absorption gas sensor includes a radiation source, detector and a radiation guide. The radiation source and detector are close together and in thermal communication. The radiation guide has a rectangular cross section and curves in a first sense, around an axis parallel to the major dimension of the rectangular cross section, and then in a second opposite sense, and again in the first sense. A relatively long path for radiation is provided in a compact device, without the attenuation of radiation which would occur if the radiation guide did not have a rectangular cross section and curved only around an axis parallel to the major dimension of the rectangular cross section. A reference measurement can be obtained by mounting a reference radiation source behind a translucent measurement radiation source and directing radiation from the reference radiation source through the measurement radiation source.

Abstract: The invention relates to a method for detecting the presence of hydrocarbons near an unmanned offshore oil platform. The method steps include monitoring reflected atmospheric and thermal radiation, detecting the presence of hydrocarbons, and generating an alert based on the presence of hydrocarbons.

Abstract: A method for detecting component concentrations in human gas emissions such as breath and gas emitted from skin. A gas sample containing a specified component is collected into a gas cell using a pump and a series of valves to draw the gas sample into the cell and control the gas pressure within the cell. A tunable optical radiation beam is passed through the gas cell and the amount of energy absorbed by the specified component may be measured indirectly by taking the difference between the incident and emerging beam energy or directly by optoacoustic methods. Concentrations of the specified component as small as 0.1 ppB may be determined. Additionally, the tunable optical radiation beam may be multiplexed for use with a plurality of systems utilizing the beam for medical purposes.

Abstract: A gas analyzer system to determine the concentration of gases in an automotive air conditioning system comprising: an infrared multi-detector device equipped with a gas analysis chamber; an emitter source emitting infrared radiation in the analysis chamber; infrared multi-detectors generating an electrical measurement quantity based on the absorption of radiation by the gas; a suction pump creating a depression inside the analysis chamber; and an electronic control unit determining a main automotive refrigerant gas concentration and the contaminant gases concentration, based on electrical measurement quantities provided by the multi-detectors and a reference electrical quantity. The control unit controls the pump to suck the gases in the analysis chamber until a condition of absence of gases is achieved, wherein the internal pressure of the chamber reaches a minimum pressure, and then determines the reference electrical quantity, based on the electrical quantity generated in the condition of absence of gases.

Abstract: A method and apparatus for the photo-acoustic identification and quantification of one or more analyte species present in a gaseous or liquid medium in low concentration utilizing a laser and a resonant optical cavity containing the medium and having within the cavity at least two partially transparent mirrors, one of which is a cavity coupling mirror and one of which is moveably mounted on an assembly responsive to an input signal.

Abstract: A radiometric measuring arrangement for measuring fill level of a fill substance in a container includes: arranged one above the other in measurement operation on a first side of the container, two or more radiometric radiators, which, in measurement operation, send radioactive radiation through the container, and which, in measurement operation, are arranged in a measuring position in the interior of the container in a pressure resistant, protective tube protruding laterally into the container; and, arranged on a second side of the container lying opposite to the radiators, at least one detector, which serves to receive radiation intensity penetrating through the container as a function of fill level and to convert such into a fill level dependent, electrical signal. The measuring arrangement permits achievement of a highly linear dependence of total detected radiation intensity on fill level.

Abstract: A volatile organic compound sensor includes a source of infrared (IR) light, a detector for detecting the IR light, and a space defined between the IR light source and the IR light detector. The space includes volatile organic compounds (VOCs). The IR light detector measures an amount of IR light transmitted through the space, the measured IR light transmitted being attenuated by VOC light absorption when in the space. An amount of the IR light attenuation is related to a concentration of the VOCs present in the space.

Abstract: A terahertz wave characteristic measurement method comprises irradiating terahertz waves at a region in which a thickness of a solution is in the range from 10 ?m to 100 ?m such that a propagation direction of the terahertz waves is in a thickness direction of the solution, the solution containing at least one type of target material to be measured, and measuring at least one of a spectral characteristic and an intensity at a particular frequency or a particular wavelength of the terahertz waves that are one of transmitted through the region and reflected from the region.

Abstract: A measuring cell adapted for a spectral analysis of a gas sample, where this measuring cell is designed and adapted to co-ordinate, from an IR generating element, emitted converging and/or diverging light beams in a direction toward an IR receiving element, by a plurality of reflections of emitted light beams from a number of reflection surfaces assigned to the inner cavity of the measuring cell, thereby creating a predetermined measuring distance in the inner cavity of the measuring cell, from the IR generating element to the IR receiving element. The cavity of the measuring cell is adapted to contain the gas sample intended for a spectroanalytical absorption measurement.

Abstract: A main stream gas analyzing device for measuring a concentration of a trace gas present in a gas stream and a method of measuring the concentration of the trace gas is disclosed. The main stream gas analyzing device includes a measuring chamber for receiving a gas flow, an infrared reflective material provided on an inner surface of the measuring chamber, an infrared radiation source directed toward the infrared reflective material of the measuring chamber and obliquely angled relative to a longitudinal axis of the measuring chamber such that infrared radiation being emitted from the infrared radiation source is reflected off of the infrared reflective material at least once, and an infrared radiation detector obliquely angled relative to the longitudinal axis of the measuring chamber to receive the reflected infrared radiation.

Abstract: A system assesses a column of gas in an atmosphere. The system includes an optical transmitter for transmitting (a) an online signal tuned to an online wavelength of gas, (b) an offline signal tuned to an offline wavelength of the gas, and (c) an optical signal for providing altimetry data. A modulator is included for modulating the online signal with a first stepped chirp waveform and modulating the offline signal with a second stepped chirp waveform. A processor assesses the column of gas, after receiving a returned online signal, a returned offline signal and a returned optical signal. A lock-in amplifier is included for (a) multiplying a returned signal with the first stepped chirp waveform to obtain a detected online signal, and (b) multiplying the returned signal with the second stepped chirp waveform to obtain a detected offline signal. The processor is configured to remove ground reflections from the optical signal to obtain scattered noise, and assess the column of gas based on the scattered noise.

Abstract: The present invention relates to a thermally compensated optical sensing system for identifying various types of liquid fuels and/or the ratio in liquid fuel mixtures on real time. In this system, an optical fiber is used as a light guide and a sensor device for determining the refractive index of liquid fuels through the principle of reflectivity. Starting from a light source, light is transmitted interiorly of the optical fiber to the test probe which is in contact with the fuel. The optical signal resulting from the interaction between light and fuel is a function of refractive indexes of the optical fiber and the fuel, the wavelength of light used, and the fuel temperature. The system proposed herein relates to the use of this optical system in liquid fuels by using optical fibers having suitable refractive indexes as a function of the fuel type and/or fuel mixture being analyzed, allowing the sensitivity of the optical system to be optimized according to application requirements.

Abstract: The construct of a specially designed air sampler and its function in order to carry out the Effortless Recalibration (ERB) procedure to an Absorption Biased (AB) designed NDIR gas sensor with the use of a Calibration Master is described.

Abstract: The invention relates to a method and to an apparatus for determining the adsorption of a gas at materials. It is the object of the invention to propose possibilities for the determining of the surface properties of materials in which statements can be obtained and very small sample volumes can be examined with sufficient measurement precision, with a reduced technical plant effort and with a reduced time effort. In the invention, a sample of a material is acted on by a gas or gas mixture within a chamber which is not transparent for electromagnetic radiation in the wavelength range between 150 nm and 25 ?m. The gas or at least a gas included in a gas mixture is adsorbed at the surface of the sample and in this respect the electromagnetic radiation emitted by the sample as a consequence of the adsorption is detected by at least one optical detector which is sensitive at least in a range of the wavelength range between 150 nm and 25 ?m.

Abstract: A disinfection system for liquids is provided that features an irradiation chamber for accommodating a liquid to be disinfected. A UV-radiator with a cladding that is transparent to UV-light is arranged in the irradiation chamber such that the UV-radiation emitted by the UV-radiator may penetrate the liquid. A first UV-sensor is arranged in the irradiation chamber such that a first attenuation characteristic with respect to the UV-light emitted by the UV-radiator may be measured with the first UV-sensor, wherein the first attenuation characteristic comprises a first aging characteristic and a first liquid attenuation characteristic.

Abstract: A control device for a mobile body makes it possible to smoothly correct the deviation of an actual posture of a base body of a mobile body, which travels with the base body thereof moving up and down, from a desired posture of the base body while restraining an overshoot or an undershoot from occurring. To determine a required manipulated variable according to a feedback control law in order to converge a state amount deviation related to the posture of the base body of the mobile body to zero, the feedback gain of the feedback control law is determined by using the time series in a period from current time to predetermined time in the future in the time series of a desired inertial force of the mobile body or the base body. The required manipulated variable is determined by the calculation of the feedback control law on the basis of the determined feedback gain and an observed value of the state amount deviation.

Abstract: An optical absorption gas sensor comprising a body having an internal wall which defines a chamber, at least one aperture in the body through which a gas sample can enter the chamber, a light source, at least one reflector, a detector assembly which extends into the chamber and has a first side and an opposite second side, a detector which measures light which is incident at least a range of angles on at least a part of a first surface of the detector assembly on the first side of the detector assembly, wherein the light source is located within the chamber on the second side of the detector assembly, the whole being configured such that light from the light source passes through the gas sample and is reflected around the detector assembly, by the at least one reflector, onto the detector.

Abstract: A re-calibration method for a dual-beam NDIR gas sensor uses a calibration curve based upon a combination of physics and sensor measurement components of the sensor to calculate sample gas concentration, then determines a second gas concentration measurement by a secondary gas standard which is used with a reversed calibration curve algorithm to adjust the sensor measurement component. The calibration curve is based upon a gamma ratio (“G”) that has been normalized by G when no sample gas is present in the sample chamber (“G0”), G being a ratio of a signal channel output (“VS”) of the sensor divided by a reference channel output (“VR”) of the sensor. The concentration (“P”) of sample gas in the sensor is calculated through use of the calibration curve by a gas detection equation of P=F(x)=F(y/G0), where x is a normalized ratio of VS/VR and y is G.

Abstract: A gas analyzer for measuring at least two components of a gas is disclosed herein. The gas analyzer comprising an emitter configured to emit infrared radiation through the gas, a filter assembly configured to permit a transmission of predetermined wavelengths emitted by the emitter, and a detector configured to receive wavelengths emitted by the emitter and penetrated through the filter assembly. The filter assembly comprises at least two tunable narrowband interference filters in series, each of the filters comprising two dielectric mirrors and an air space between the two dielectric mirrors to tune one of the filters to different transmission band than another of the filters.

Abstract: An NDIR gas sensor takes advantage of a conventional packaging embodiment commonly used to house detectors of all kinds comprising a can, header and a dish sample chamber all welded together to form a single detector unit. The can forms the top, a hollowed out header body forms the middle and a custom dish sample chamber forms the bottom of a completely functioning NDIR gas sensor. Whereas the header body not only accommodates all the optoelectronic and optical parts on its top surface providing the required signal processing functions for the gas sensor, part of its body is excavated below to accommodate a custom dish sample chamber in communication with the gas outside whose concentration level is to be measured. A lens and windows are also fabricated on the top part of this header body so that infrared radiation can enter the dish sample chamber below and then be redirected back above for signal processing.

Abstract: The present invention describes a system and method for accurately measuring the concentration of a substance within a filter housing. A concentration sensor and a communications device are coupled so as to be able to measure and transmit the concentration of a particular substance within the filter housing while in use. This system can comprise a single component, integrating both the communication device and the concentration sensor. Alternatively, the system can comprise separate sensor and transmitter components, in communication with one another. In yet another embodiment, a storage element can be added to the system, thereby allowing the device to store a set of concentration values. The use of this device is beneficial to many applications. For example, the ability to read concentration values in situ allows integrity tests to be performed without additional equipment.

Abstract: The invention relates to a method of ensuring the safety of the components of the drive train of a vehicle equipped with a heat engine, before or during its startup phase following a deterioration of the quality of the fuel contained in the tank (2) and the fuel feed system of the engine, said method comprising a step of diagnosing the type and extent of the deterioration of the quality of the fuel, said step being based on the measurement of the interactions between an electronmagnetic radiation and the constituent molecules of the fuel, said measurement being performed by a system of analysis, and a step of activating a system (13) to ensure the safety of the components of the drive train as a function of the results of the analysis step.

Abstract: System flow path designs that minimize the impact of gas diffusion sources and sinks. By reducing the magnitude of parasitic sources and sinks, lower rates of photosynthesis and transpiration can be more accurately measured, e.g., without the need for extensive empirical compensation. According to one aspect, a gas exchange analysis system includes a sample chamber defining a measurement volume for analysis of a sample, the sample chamber having an inlet and an outlet, wherein the internal surface(s) of the chamber defining the measurement volume are metal plated. The system also typically includes a source of gas coupled with the inlet of the sample chamber, and a gas analyzer coupled with the outlet of the sample chamber and configured to measure a concentration of one or more gases exiting the chamber, whereby the metal plated internal surface(s) of the chamber reduces sorption of the one or more gases within the chamber.

Abstract: System flow path designs that minimize the impact of gas diffusion sources and sinks. By reducing the magnitude of parasitic sources and sinks, lower rates of photosynthesis and transpiration can be more accurately measured, e.g., without the need for extensive empirical compensation. According to one aspect, a sensor head for use in a gas exchange analysis system includes a sample chamber defining a measurement volume for analysis of a sample, the sample chamber having an inlet and an outlet, and a flow splitting mechanism located proximal to the sample chamber, the mechanism configured to split a gas flow received at an input port from a remote source to a first output port and to a second output port, wherein the first output port is coupled with the inlet of the sample chamber.

Abstract: The present invention describes a system and method for accurately measuring the concentration of a substance within a filter housing. A concentration sensor and a communications device are coupled so as to be able to measure and transmit the concentration of a particular substance within the filter housing while in use. This system can comprise a single component, integrating both the communication device and the concentration sensor. Alternatively, the system can comprise separate sensor and transmitter components, in communication with one another. In yet another embodiment, a storage element can be added to the system, thereby allowing the device to store a set of concentration values. The use of this device is beneficial to many applications. For example, the ability to read concentration values in situ allows integrity tests to be performed without additional equipment.

Abstract: A method of measuring methanol vapor concentration on a real-time basis and a methanol vapor concentration measuring apparatus used in fuel cells. The method of measuring methanol vapor concentration involves using an absorption spectrometry technique, that is, after measuring intensities I0 and I1 of light of a laser before and after passing through a space filled with methanol vapor and into which light is irradiated, the methanol vapor concentration is calculated by substituting the intensities I0 and I1 into an equation defined as I1/I0=exp (K·L·C), where K represents the absorption coefficient, L represents the length of the space through which the laser passes, and C represents the methanol vapor concentration.

Abstract: An NDIR gas sensor takes advantage of a conventional packaging embodiment commonly used to house detectors of all kinds comprising a can, header and a dish sample chamber all welded together to form a single detector unit. The can forms the top, a hollowed out header body forms the middle and a custom dish sample chamber forms the bottom of a completely functioning NDIR gas sensor. Whereas the header body not only accommodates all the optoelectronic and optical parts on its top surface providing the required signal processing functions for the gas sensor, part of its body is excavated below to accommodate a custom dish sample chamber in communication with the gas outside whose concentration level is to be measured. A lens and windows are also fabricated on the top part of this header body so that infrared radiation can enter the dish sample chamber below and then be redirected back above for signal processing.

Abstract: An elliptical photo-acoustic spectrometer chamber design will result in a larger intensity signal at the pick-up microphone and allow high frequency light modulation. This makes the spectrometer have a lower limit of detection threshold, and will increase the signal to noise ratio in general for the instrument, resulting in a more sensitive instrument allowing more precise measurements.

Abstract: To enable an air velocity of sampling air to be precisely measured, a smoke detector (S) includes: a smoke detection part (22) connected to a sampling pipe (11); a fan (12) that sucks sampling air (SA) into the sampling pipe; and an air velocity sensor (15) that measures an air velocity of the sampling air within the sampling pipe. The air velocity sensor (15) is disposed at a primary side of the fan (12), and a straightening vane (25) is disposed between the air velocity sensor (15) and a suction port (12a) of the fan (12).

Abstract: A device comprising an acoustic detector, one or more thermal sensing elements coupled to the acoustic detector, and a light source. A method comprising directing a beam of light at a wavelength at or near one or more thermal sensing elements, wherein the thermal sensing elements are coupled to an acoustic detector, determining a resonance frequency of the acoustic detector, wherein the acoustic detector is coupled to one or more of the thermal sensing elements, and measuring the response of the acoustic detector to detect optical radiation absorption proximate to or at the surface of one or more thermal sensing elements.

Abstract: Two detector elements are optically isolated by having them mounted (die-attached) on the same header so that the thermal tracking of the detectors respectively for the signal and reference channels is close to ideal. Furthermore, such an optical isolation technique or cross-interference suppression between the two detector elements mounted on the same header also allows the use of only one and the same narrow band pass interference filter covering both detectors. Thus the thermal tracking of the filters respectively for the signal and reference channels is also close to perfection as both channels share the same filter.

Abstract: It is an object of the present invention to provide a fuel property detection apparatus that excels in durability and reliability and is capable of accurately detecting the biofuel concentration in a mixture of hydrocarbon fuel and biofuel with a compact and simple configuration. A fuel property sensor 22 includes a light-emitting device 28 and a light-receiving device 32, which detect the optical transmittance of a fuel in a fuel path 26; and a light-emitting device 36 and a position sensitive device 38, which detect the refractive index of the fuel. As the optical transmittance correlates with the RME concentration of the fuel, the RME concentration can be calculated from the detected optical transmittance. As the refractive index correlates with the cetane number of the fuel, the cetane number can be calculated from the detected refractive index. The optical transmittance is detected through the use of light within a wavelength range of 640 nm to 680 nm.

Abstract: A gas analyzer capable of measuring a concentration of a gas component in gas at sensor units provided at a plurality of positions in real time by decreasing the number of signals input from the sensor units to an analyzer so as to reduce a data amount input to the analyzer and a gas analyzing method. The gas analyzing method includes the steps of: demultiplexing laser light by a demultiplexer into measurement laser light and reference laser light; letting the measurement laser light pass through gas to be received by a photoreceiver; finding an absorption spectrum absorbed by a gas component in the gas based on a light intensity of the received measurement laser light and of the reference laser light; and analyzing the absorption spectrum to measure a concentration of the gas component.

Abstract: The present invention describes a system for accurately measuring the concentration of a substance within a filter housing. A concentration sensor and a communications device are coupled so as to measure and transmit the concentration of a particular substance within the filter housing while in use. This system allows the operator to certify the integrity of the filters within the filter housing at the customer site without additional equipment. In one embodiment, a tracer gas, such as helium or hydrogen, is added to a carrier and injected into the system. The concentration of tracer gas at a specific operating transmembrane pressure is indicative of bubble pointing specific pores in the filter. This test will give a more sensitive indication of the bubble point and the presence of defects than a standard diffusion test. In a second embodiment, two gasses, in a known ratio, are introduced into the filter housing.

Abstract: A gas measurement system includes a housing adapted to be mounted on an airway adapter, and a luminescence quenching gas measurement assembly disposed in the housing. The luminescence quenching gas measurement assembly includes a source disposed in a first plane, and at least one detector also disposed in the first plane.

Abstract: To enable an air velocity of sampling air to be precisely measured, a smoke detector (S) includes: a smoke detection part (22) connected to a sampling pipe (11); a fan (12) that sucks sampling air (SA) into the sampling pipe; and an air velocity sensor (15) that measures an air velocity of the sampling air within the sampling pipe. The air velocity sensor (15) is disposed at a primary side of the fan (12), and a straightening vane (25) is disposed between the air velocity sensor (15) and a suction port (12a) of the fan (12).

Abstract: An apparatus for detecting a property of fuel detects the property of fuel at the time of fuel supply. A measuring chamber member is provided to a fuel tank. The greater portion of fuel supplied from a fuel supply nozzle falls down from a fuel supply aperture via a flow outlet into the fuel tank. However, a part of the fuel remains in a measuring space defined between a portion below the flow outlet and a bottom portion. A fuel property detection sensor is fitted to a main body so as to oppose the measuring space. When application of a cap to the fuel supply aperture has been detected by a fuel supply cap sensor, if increase of the remaining fuel amount has been detected by a remaining fuel amount sensor, or if the engine is started, a controller measures the property of the fuel with the fuel property detection sensor.

Abstract: This invention relates to a compact cavity ring down spectrometer for detection and measurement of trace species in a sample gas using a tunable solid-state continuous-wave mid-infrared PPLN OPO laser or a tunable low-power solid-state continuous wave near-infrared diode laser with an algorithm for reducing the periodic noise in the voltage decay signal which subjects the data to cluster analysis or by averaging of the interquartile range of the data.

Abstract: Near IR spectroscopy may be used for determining the coke generation tendency of a hydrocarbon. The coke generation tendency of hydrocarbons may be used to control refining conditions. An apparatus for determining the coke generation tendency of hydrocarbons comprising a near infrared spectrophotometer and other components may be used to make the determinations continuously.

Abstract: A measurement device and a method for analyzing a sample gas by infrared absorption spectroscopy are described. The measurement device comprises: a measurement chamber with the sample gas to be analyzed, a laser being arranged in relation to the measurement chamber such that light being emitted from the laser radiates through the measurement chamber, a detection device detecting the light being emitted from the laser and radiated through the measurement chamber, and an evaluation unit evaluating signals generated by the detection device regarding a light absorption occurred in the measurement chamber.

Abstract: A chemical vapor sensor system and method are provided, wherein the system includes an air input device, a light source, a detector, a sample chamber, and a processor. The air input device includes at least a sample input port, a reference input port, and an output port. The light source emits light, and the detector receives at least a portion of the emitted light. The sample chamber is in fluid communication with the output port, wherein the air alternatively enters the air input device from the sample input port and the reference input port and enters the sample chamber. The processor receives an output signal from the detector based upon a detection of at least carbon dioxide and ethanol in the air in the sample chamber, wherein the processor determines a blood alcohol content of a person whose breath was received in the sample input port.

Abstract: Two detector elements are optically isolated by having them mounted (die-attached) on the same header so that the thermal tracking of the detectors respectively for the signal and reference channels is close to ideal. Furthermore, such an optical isolation technique or cross-interference suppression between the two detector elements mounted on the same header also allows the use of only one and the same narrow band pass interference filter covering both detectors. Thus the thermal tracking of the filters respectively for the signal and reference channels is also close to perfection as both channels share the same filter.

Abstract: An NDIR gas sensor is housed within a mechanical housing made up of a can and a header housing. The header housing body contains a tunnel waveguide sample chamber. The header housing also has a top surface with a pair of windows formed in it and a signal detector, a reference detector, a MEMS source and a signal processor mounted to it. The can has inner reflective surfaces and the reference detector and the signal detector are affixed to the top surface so that the inner reflective surfaces of the can and the tunnel waveguide sample chamber create a signal channel path length detected by the signal detector that is greater than a reference channel path length detected by the reference detector and an absorption bias between the signal and reference outputs can be used to determine a gas concentration in the sample chamber.

Abstract: The present invention describes a method for measuring the concentrations of species present at one point of a separation unit functioning in simulated moving bed mode (SMB), using an immersing probe located at one point in the unit or on one of the streams entering or leaving said unit, and a thermocouple located in the vicinity of the immersing probe, in which a Raman spectrum obtained using a laser source functioning at a wavelength of 785 nm is utilized. Application of the method to controlling and regulating a SMB xylenes separation unit.

Abstract: An analysis apparatus for analyzing a gas by a terahertz wave or an infrared ray comprises a generator for generating the terahertz wave or the infrared ray; a trapping unit having a trapping film for trapping a gas and being placed to be capable of causing interaction between the gas trapped by the trapping film and the terahertz wave or infrared ray generated by the generator; and a detector for detecting the interaction of the gas with the terahertz wave or infrared ray; wherein the trapping unit comprises a structure for contact with a site evolving the gas; and the structure holds the trapping film separately from the site.