Abstract: A gas sensor (1) with a detector element (2), which is specific to a gas to be measured and sends a measured signal that depends on the measured gas concentration, has increased measuring sensitivity for measurements in the concentration range from less than 1 ppb to a few ppb. The detector element (2) is exposed in a gas admission adapter (4) to a gas to be measured via a diaphragm (3) arranged in front of the detector element (2), wherein the gas admission adapter (4) has at least a first opening (20) for the entry of the gas to be measured as well as at least a second opening (30), which is connected with a pressure modulator, which generates periodic gas pressure vibrations in the gas admission adapter (4) and is designed, for example, as a pump (5).

Abstract: A device and method for quantifying an impurity in an input gas stream. The device and method employ a catalyst to convert the impurity to a detectable species in an output gas stream, and the concentration of the detectable species is then measured by means of a detector.

Abstract: A sensor for measuring a physical property of a measuring gas, in particular the oxygen concentration or the temperature in the exhaust gas of an internal combustion engine in a motor vehicle, has a housing, a measuring element whose end section protrudes from the housing, a connector plug mounted on the end section, and a housing shell covering the end section and connector plug with a radial clearance, one shell end of the housing shell being attached to the housing and the other shell end being sealed. To prevent electromechanical breakage in the sensor in the event of extreme vibration stresses or accelerations of the vehicle, the free space within the housing shell is completely filled with a non-conductive granulate.

Abstract: This invention is to a microreactor type of reaction and analysis system. The system includes a chemical reaction chamber having internal conduits through which a chemical reactant, such as a reaction gas, can be fed. The conduits for transporting fluids such as reactant, carrier gas and balance gas are in appropriate communication such that the amount of reactant going directly to a catalyst located in the reaction chamber can be optimally controlled. The system is highly useful for studying the kinetics of a chemical reaction.

Abstract: A gas sensor assembly detects a constituent in a gaseous stream. The assembly comprises: (a) a mounting surface, (b) a sensor mounted on the mounting surface and sensor capable of generating a detectable signal in the presence of the constituent, and (c) an enclosing structure. The enclosing structure comprises: (i) a walled component having a pair of vertically spaced ends and mounted at one end on the mounting surface so as to circumscribe the sensor, and (ii) a gas-permeable membrane attached at the other end of the walled component, thereby defining an interior volume within said enclosing structure. Flowing the gaseous stream across the membrane infuses a portion of the gaseous stream into said interior volume containing the sensor.

Abstract: A system and method for detecting the presence of submicron sized particles in a sample taken from the environment includes a collecting a sample from the environment and purifying and concentrating the submicron particles in a sample based on the size of the particles. The purified and concentrated particles are detected with an apparatus which includes an electrospray assembly having an electrospray capillary, a differential mobility analyzer which receives the output from the capillary, and a condensation particle device for counting the number of particles that pass through the differential mobility analyzer.

Abstract: Disclosed is a method for measuring the available remaining hydrogen capacity of a non-replaced hydrogen storage canister. After the original hydrogen capacity of the hydrogen storage canister is read, the used hydrogen capacity of the hydrogen storage canister is read and remaining hydrogen capacity formula is employed to determine the available remaining hydrogen capacity of the hydrogen storage canister. For a fully charged or newly-installed hydrogen storage canister, the process includes reading the number of cycles of operation of the hydrogen storage canister, reading the original hydrogen capacity of the hydrogen storage canister, reading the used hydrogen capacity of the hydrogen storage canister, and then employing the remaining hydrogen capacity formula to determine the available remaining hydrogen capacity of the hydrogen storage canister.

Abstract: A reader is provided that, itself, addresses the issue of damage or degradation to arrays within the reader by virtue of air exposure. In doing so, experimental variability is reduced, and read/scan signal strength degradation is minimized for arrays/slides scanned or otherwise read toward the end of a run. The subject scanners employ a filter that reduces the amount of chemicals in the air inside the device that are harmful to the array, or the dye on the array. The implementation of adding a chemical filter to the reader device may be such that air is either drawn into or, alternatively, pushed through the filter into the same. It is possible that the entirety of the device may be provided with filtered air, or just the region holding slides to be scanned. Array readers so-constructed as well as associated methodology involving filtering incoming air while reading arrays are covered.

Abstract: The sensing apparatus for a vehicle includes a case having an opening part formed so as to communicate with an outside. A printed circuit board is disposed inside of the case, and includes a circuit unit. A noxious gas sensing part is electrically connected with the circuit unit for sensing a noxious gas of an external air inflowing through the opening portion, and for outputting a sensing signal. A connector is disposed at least partially with the case, one end thereof being directly connected with the circuit unit, and the other end thereof being directly connected with an external device.

Abstract: The present invention provides for novel hydrogen sensors and methods for making same. In some embodiments, such novel hydrogen sensors are continuous-range hydrogen sensors comprising Pd—Ag nanoparticles arrayed as nanowires or two-dimensional shapes on a resistive surface. Such continuous-range hydrogen sensors are capable of measuring a wide range of hydrogen gas concentration over a wide temperature range. Unlike existing hydrogen sensors that experience a large change in resistance at a certain hydrogen concentration, the continuous-range hydrogen sensor of the present invention changes resistance continuously over a broad range of hydrogen concentration. This continuous change varies slowly with hydrogen concentration and is predictable such that the continuous-range hydrogen sensor can be used to measure hydrogen concentration continuously from a few ppm to 40,000 ppm level or higher over a broad range of temperatures (e.g., ?40° C. to +150° C.).

Abstract: An air quality monitor having multiple sensors deployed in an electric circuit returns a single sign indication of atmospheric impurity regardless of whether the impurity gas is of the oxidizing or reducing type. Each sensor employs a gas sensitive material that exhibits a response in the form of a change in electrical resistance of the material in the presence of a gas and that exhibits a negligible response to changes in the moisture content of the atmosphere. A powder is dried and calcined and the result is ground into a fine powder and pressed into a desired shape to make the gas sensitive material. Adding a binder during the pressing and firing the shaped powder results in a gas sensitive material with porosity. Gas is flowed to the gas sensitive material and the resulting change in resistance is measured and returned as a single sign indication of atmospheric impurity.

Abstract: A protective coating for a surface comprising a layer permeable to hydrogen, said coating being deposited on a catalyst layer; wherein the catalytic activity of the catalyst layer is preserved.

Abstract: A method and apparatus for rapidly preprocessing and analyzing chemical substances, which places a vaporization bottle containing a sample inside a microwave device and uses a magneton driving device to drive the magneton inside the vaporization bottle to rotate as to stir the sample liquid even. In the meantime, the radiation of the electromagnetic wave of the microwave device is used to activate the molecules of the sample liquid to move, causing the tested chemical substance in the sample liquid to be vaporized in a very short time. Therefore, the tested chemical substance can be absorbed or adsorbed by the absorbing medium to greatly reduce the sample preprocessing time and increase the quantity of the tested chemical substance sample. The detection limits of a tested chemical substance are therefore lowered without using organic solvents.

Abstract: The invention relates to a high sensitive semiconductor type hydrogen sensor, an alarm of hydrogen which incorporates this sensor and a method of sensing hydrogen concentrations by using this sensor.

Abstract: A gas monitoring device for monitoring gas levels within a chamber is provided. The gas monitoring device includes a housing having a probe with a sensor disposed on the probe. The probe extends through the housing and into a chamber such that the sensor is within the chamber. The housing includes a first passageway disposed about the probe and second passageway disposed about the first passageway. During operation of the gas monitoring device, a temperature adjusting medium enters the second passageway through an inlet of the housing and then enters into the first passageway via the second passageway. As the temperature adjusting medium travels through the first passageway, the temperature adjusting medium adjusts the temperature of the probe. The temperature adjusting medium adjusts the temperature of the probe through thermal conduction. As the temperature of the probe adjusts, the temperature of the sensor also adjusts through thermal conduction.

Abstract: A precision gas flow meter that is capable of measuring small flow rates of gasses precisely in the range of 0.01 to 10 L per minute. The meter is designed to measure the gas flow in small volume increments of predetermined value, and therefore can be used to measure a gas flow that is continuous or discontinuous. The flow meter can be used to measure the gas production rates from many processes, including biological reactors, chemical reactors, and thermal-chemical reactors. The device can also be used to meter the gases that are required in small or minute volumes.

Abstract: The invention relates to a process for the detection of hydrocarbons other than methane in a gas predominantly or essentially comprising oxygen, as well as methane and the said hydrocarbons other than methane, the said process comprising: a stage of detection of the combined hydrocarbons in the said gas, providing a first value for the combined hydrocarbons, a stage of combustion of the hydrocarbons other than methane, a stage of detection of methane in the said gas, providing a second value, a stage of calculation of the amount of hydrocarbons other than methane by the difference between the first value and the second value. The invention also relates to a device for implementing this process.

Abstract: The invention relates to a sample cell with a glass body comprising a gas inlet and a gas outlet and at least one orifice, a plane glass window is fused into the orifice, the shape and size of the window corresponds to the shape and size of the orifice, the orifice is limited by a rim, the rim is wider than the thickness of the window, the rim of the window is fused with the rim of the orifice. The invention further relates to a method of producing the sample cell. The window is inserted into the orifice. The rim of the orifice is heated several times from the exterior in such a way that the glass melts and a fused joint is formed between the window and the rim of the orifice. The sample cell produced by the method has a particularly rigid joint between the window and the glass body. Therefore, this glass cell is able to withstand pressures above 10 bar and allows the passage of light without lens effects owing to its plane-parallel windows. The sample cell is used in a polarizer for inert gas.

Abstract: A gas detector capable of accurately measuring particular components (odors or the like) contained in an ambient gas to be measured, being compact, and capable of being easily formed to be portable, or producing low noise and capable of being small-sized. Having zero gas cylinder (9) as a supplying unit of a zero gas and component parts disposed within its enclosure (2) and using syringe (3) as a gas intake/exhaust unit, it alternately introduces a test gas, i.e., an ambient gas taken in from outside enclosure (2) through piping (12a), and the zero gas supplied from zero gas cylinder (9) into sensor unit (7) and measures the test gas, while having operation of each unit controlled by data processor (11). Thus, accurate measurement of the test gas is achieved by relatively comparing results of measurement on the gases at each measurement. In addition, gas detector (1) can be moved to a spot where measurement is to be made to have the test gas there measured.

Abstract: Systems and methods for mass flow controllers which minimize false flow conditions and display a reduced sensitivity to pressure transients are disclosed. Pressure gradients that exist within the volume of a mass flow controller fluid path are minimized in order to limit the potential energy contained in compressed or pressurized process gas. Additionally, process gas pressure may be monitored using a pressure sensor. This pressure signal is utilized in conjunction with a control algorithm to cancel the detrimental effect of certain flow components. These mass flow controllers may be used as drop in replacements for legacy mass flow controllers and reduce the cost of gas sticks due to elimination of discrete components such as pressure regulators, gas filters, pressure transducers, local pressure displays, isolation valves, seals, etc.

Abstract: A powder filler is stuffed in a filler space defined between a housing and a gas sensing element so as to airtightly seal a clearance between the housing and the gas sensing element. The powder filler contains grains whose diameter is in a range from 80 ?m to 5,000 ?m when measured before being stuffed into the filler space. A weight percentage of the grains having the diameter of 80 ?m to 5,000 ?m is equal to or larger than 80% with respect to an overall weight of the powder filler.

Abstract: Method for the control of a controlled atmosphere for the storage of plant products in at least one storage- or transport space, where a) the concentration of at least one trace gas that is produced by the plant products and has a share of less than 1% of the controlled atmosphere is measured at least twice at different times; b) the degree of change in the concentration of the trace gas is derived from at least two measuring values as the measure of the production rate of the plant product for said trace gas; c) the control variables for the composition in the controlled atmosphere are determined depending on the degree of change in the concentration of the trace gas, and d) the composition of the controlled atmosphere is adjusted according to the control variables.

Abstract: A chemically functionalized cantilever system has a cantilever coated on one side thereof with a reagent or biological species which binds to an analyte. The system is of particular value when the analyte is a toxic chemical biological warfare agent or an explosive.

Abstract: A flow-through monitor for detecting molecular contamination (MC) within a fluid flow. The monitor has a diffusion chamber having an inlet port and an outlet port, and a structure for supporting a fluid flow from the inlet port to the outlet port. The structure includes a flow gap causing a diffusion of molecular contaminants into the diffusion chamber, while substantially preventing, for a rate of the fluid flow above a predetermined magnitude, particulate contaminants within the fluid from entering the diffusion chamber. A SAW device detects molecular contamination interior to the diffusion chamber. Fluid input to the flow-through monitor may be diluted by a pure fluid for extended monitor life. A system for aggregate sampling connects an ensemble manifold upstream of the flow-through monitor. A system for triggered sampling connects a sample preconcentrator downstream of the flow-through monitor. A chemically selective membrane may be located between the flow gap and the SAW.

Abstract: Screening of items for the presence of contaminants, such as explosives residue, is accomplished by subjecting an item loaded into a pressure chamber to a pressure substantially in excess of atmospheric pressure conditions and rapidly decompressing the item to the ambient atmospheric pressure. The rapid decompression serves to scavenge vapors and particles from the exterior and interior of the item and any objects it contains. A sample of the vapors and particles removed from the item by the rapid decompression is sampled and is tested to determine whether a predetermined contaminant is present in the sample. Depending on the types of contaminants for which the sample is tested, it is possible to detect whether explosives, biological or chemical agents, and/or narcotics residues are present on or in the item being screened.

Abstract: A self-contained closed loop system and method for detecting contaminants in, on, and around objects. The system includes an air duct subsystem connecting at least one sensor to a sealed housing containing a rotating container. Air from the sealed housing is circulated past a sensor to detect, for example, biological or chemical contaminants. If a contaminant is detected, an indicator is set and a contaminant neutralizer is optionally injected into the air duct subsystem.

Abstract: A device for detecting sulfuryl fluoride, in which the gas specimen to be examined is subjected to pyrolysis with ensuing detection of a pyrolysis product, is to be improved for the sake of achieving a mobile, economical structure. To attain this object, in a preliminary tube (1) for pyrolysis, there is a chemical layer (5) of pyrophoric iron, and as an indicator system for the pyrolysis product, a test tube (2) for hydrogen fluoride is used.

Abstract: Devices and techniques for estimating the concentration of one or more agents in a fluid environment employ a plurality of measurements of a sensor attribute that changes in response to an agent. Measurements taken before the agent/reagent combination reaches a steady-state may be used. The plurality of measurements are processed using a nonlinear, parametric model of the interaction between the sensor and the agent to determine the concentration of the agent. The model takes into account the finite capacity of a sensor reagent. The model characterizes the interaction of individual agent/reagent combinations with a set of parameters. These parameters require minimal testing to calculate. The invention enables the response of a sensor to an agent over the entire range of agent concentration levels to be efficiently and accurately characterized. The invention also enables the prediction of collective responses given parameters characterizing a plurality of agent/reagent combinations.

Abstract: A sampling system for detecting an analyte, comprising a diaphragm pump, a buffer chamber, a sensor head and intake port. The pump includes a chamber for receiving fluids via first and second ports. A buffer chamber is located at the second port for holding a quantity of air, and a sensor head is adapted to identify the presence of a desired analyte and produce a signal in response to the quantity identified. Preferably the diaphragm pump has a volume of gas per stroke capacity slightly larger than the volume of the sensor head such that the pump chamber has a greater volume than the buffer chamber and the buffer chamber has about the same volume as the sensor head. A sensor intake port intakes a sample potentially containing the analyte for contact with the sensor head upon operation of the diaphragm pump and out of the sensor head by jet-action caused by rapid movement of the diaphragm pump. A filter may be used for filtering air drawn through the pump chamber.

Abstract: A method and device for measuring release rates of contaminants in at least one of a fast release mode and a slow release mode in which a volatile liquid sample is introduced into a sealed transparent reactor vessel having at least one sorbent contained within the transparent reactor vessel and a separator for preventing direct contact between the at least one adsorbent and the at least one volatile liquid sample in the transparent reactor vessel, whereby substantially zero headspace is maintained within the transparent reactor vessel. At least one solvent soluble constituent present in the at least one volatile liquid sample is passed through the separator, resulting in sorption of the at least one solvent soluble constituent by the at least one sorbent. In accordance with one preferred embodiment, the separator is a dialysis bag contained in the transparent reactor vessel into which the resin is placed.

Abstract: A method for controlling production process by performing near-infrared absorptiometric analysis by simple procedures in an accurate manner, in which control of production process step can be realized at a high accuracy by simple operation based on the thereby obtained analytical results, the said method comprising taking each absorbance spectrum for a plurality of standard samples in an analysis range including near-infrared region, calculating the average intensity and standard deviations for each of selected wave lengths to construct a data base, taking an absorbance spectrum in the said analysis range for each of analysis samples and comparing it with the data base in order to judge whether or not the intensity of the absorbance spectrum is within an assumed tolerance limit determined based on the stored standard deviations of the standard samples in the data base to thereby obtain control data by comparing, when wave lengths at which the observed intensity is outside the tolerance limit are present, thes

Abstract: A hydrogen sensor includes a first electrode 3 and a second electrode 4 provided in contact with a proton conduction layer 2; a gas diffusion controlling portion 6 provided between a measurement gas atmosphere and the first electrode 3; and a support element (1a, 1b) for supporting the proton conduction layer 6, the first electrode 3, the second electrode 4, and the gas diffusion controlling portion 6. Hydrogen contained in a measurement gas introduced via the gas diffusion controlling portion 6 is dissociated, decomposed, or reacted by applying a voltage between the first electrode 3 and the second electrode 4 to thereby generate protons. Hydrogen concentration is obtained on the basis of a limiting current generated as a result of the generated protons being pumped out via the proton conduction layer 2 from the first electrode 3 side of the proton conduction layer to the second electrode 4 side of the proton conduction layer.

Abstract: Methods, systems and sensor arrays are provided implementing techniques for detecting an analyte in a fluid. The techniques include providing a sensor array including at least a first sensor and a second sensor in an arrangement having a defined fluid flow path, exposing the sensor array to a fluid including an analyte by introducing the fluid along the fluid flow path, measuring a response for the first sensor and the second sensor, and detecting the presence of the analyte in the fluid based on a spatio-temporal difference between the responses for the first and second sensors.

Abstract: A system and methods of the present invention advantageously provide efficient mail processing and handling that, as compared to existing procedures, enhances detection of biological, germ, chemical, or other harmful agents within the mail being processed or handled. A system and methods additionally provide a higher level of quality and consistency for processing and handling mail so that concerns over contamination of postal workers and potential mail recipients are reduced. A system and methods further provide enhanced detection of contaminated mail contents, mail, mail equipment, mail containers, and mail personnel due to exposure or contact with harmful agents associated with mail. The system and methods preferably includes the use of at least one harmful agent sensor associated with mail processing equipment.

Abstract: Of a gas detector 100, a chamber 105 formed between a center cover 150 and a cover 160 is a part of an air flow channel AF. A first shielding plate 165 is provided in the chamber 105. Water droplets that have entered the chamber from a chamber entrance 103 with air hit and adhere to an entrance-opposed surface 165E of the first shielding plate 165. The water thus adhering to the surface is pushed by the air flowing along the entrance-opposed surface 165E and by gravity, to thereby advance downward. The water then drips downward and is accumulated on a bottom wall surface 105WD which serves as an upper surface of a bottom wall section 161WD. The water is pushed by the flow of air, to thereby advance toward a chamber exit 104. The water is then drained downward from the chamber exit 104.

Abstract: A circular chemiresistor for use in microchemical sensors. A pair of electrodes is fabricated on an electrically insulating substrate. The pattern of electrodes is arranged in a circle-filling geometry, such as a concentric, dual-track spiral design, or a circular interdigitated design. A drop of a chemically sensitive polymer (i.e., chemiresistive ink) is deposited on the insulating substrate on the electrodes, which spreads out into a thin, circular disk contacting the pair of electrodes. This circularly-shaped electrode geometry maximizes the contact area between the pair of electrodes and the polymer deposit, which provides a lower and more stable baseline resistance than with linear-trace designs. The circularly-shaped electrode pattern also serves to minimize batch-to-batch variations in the baseline resistance due to non-uniform distributions of conductive particles in the chemiresistive polymer film.

Abstract: A multi-function detecting pen is described. The multi-function detecting pen includes a head module, a detecting chips module, a power module, a lighting module, and a control module. The head module is disposed at a front portion of the pen and the detecting chips module is followed. The detecting chips module may include at least one pressure detecting chip for measuring a pressure, e.g. tire pressure, and/or a gas detecting chip for measuring a gas concentration, e.g. alcohol concentration. The detecting chips module may further include a temperature detecting chip for measuring a temperature, e.g. ambient temperature or tympanum temperature. The head module may further include a switchable or a replaceable adapter for coupling to the corresponding object and keeping the head module clean.

Abstract: A hydrogen gas sensor and/or switch fabricated from arrays nanowires composed of metal or metal alloys that have stable metal hydride phases. The sensor and/or switch response times make it quite suitable for measuring the concentration of hydrogen in a flowing gas stream. The sensor and/or switch preferably operates by measuring the resistance of several metal nanowires arrayed in parallel in the presence of hydrogen gas. The nanowires preferably comprise gaps or break junctions that can function as a switch that closes in the presence of hydrogen gas.

Abstract: An improved structure of a gas sensor designed to withstand physical impact which may result in damage such as cracks to a sensor element built in the gas sensor. Specifically, the gas sensor includes a buffer provided by a clearance between an air cover a porcelain insulator. The clearance is in a range of 1 to 2.5 mm at a minimum. The gas sensor may alternatively have a harder portion in the air cover which has a Vickers hardness of 200 to 400. The gas sensor may alternatively have a rigidity enhancer in the air cover which works to provides an increased rigidity to the air cover.

Abstract: A device and method of making same. The device or hydrogen detector has a non-conducting substrate with a metal film capable of absorbing hydrogen to form a stable metal hydride. The metal film is being on the threshold of percolation and is connected to mechanism for sensing a change in electrical resistance in response to the presence of hydrogen in contact with the metal film which causes an increase in conductivity.

Abstract: The disclosed apparatus and methods allow collection of concentrated samples of content in shipping packages without unsealing the package by forcing airflow via existing hidden gaps or, if necessary, creating one by a small incision. The air is injected into the hidden gaps by either probe or socket device to disturb and agitate contents inside the package, causing the contents to loosen and blending particulates on the surface into the air stream. Airborne particles are channeled into a detection device, where the particulates are concentrated. Display and warning apparatus receive and record the analysis results from the detection device. If the analysis finds that predetermined selection and sensitivity criteria for target hazard or contraband material are met, then the warning apparatus initiates the appropriate alert protocols.

Abstract: A thermal sensor has a substrate defining a reaction chamber. The reaction chamber has an inlet for conducting sample into the reaction chamber, a reaction surface and an orifice adjacent the reaction surface defining an outlet from the reaction chamber. The reaction surface is coated with a sorbant for binding agents in the sample. A heat transducer in the substrate and in proximity to the reaction surface is configured for heating the reaction surface.

Abstract: An apparatus and method for sensing chemical and/or biological analytes includes a deflectable arm of a microcantilever at least partially embedded within a sensing element. A gaseous or liquid medium which may include the analyte being detected is introduced to the sensing element. The sensing element undergoes volumetric expansion or contraction in the presence of the analyte sought to be detected, typically by adsorbing the analyte. The volumetric change of the sensing element causes the deflectable arm to deflect. The deflectable arm includes at least one measurable physical property which changes when the arm deflects. Detecting means are provided to measure the change in the physical property to determine the presence and amount of analyte present. An array of microcantilevers in which each microcantilever is dedicated to detecting a particular analyte which may be included in the medium, is also provided.

Abstract: The intensity of an odour can be quantified by determining what is the response of an odour sensing device to that odour, then transforming the response data to an odour intensity value based on transformation data relating to a set of selected reference odours. The transformation data includes organoleptic data indicating how odour intensity values assigned to the set of reference odours by a sensory panel depend upon the concentration of the reference compounds and includes data indicating how the response data of the odour sensing device when exposed to the set of reference odours depends upon the concentration of the reference compounds. The reference odours may be basic odours defining the dimensions of a multi-dimensional space in which odours can be defined.

Abstract: A system and method are provided for monitoring the levels of combustible gas in a gas stream. The system includes means for controlling the relative humidity of the the gas stream to maintain a humidity level in the performance range of combustible gas sensors. A number techniques are illustrated for achieving the humidity control, including, secondary phase separations, mixing the gas with dry air and adjusting of the gas stream temperature.

Abstract: A sniffing leak detector includes a handpiece, supporting a sniffing tip, the detector further including a gas sensor. To promote longer life and obtaining more accurate results, the leak detector is equipped with an acceleration sensor for recording the movements of the handpiece.

Abstract: A gas sensor equipped with a protective gas cover which defines therein a gas chamber to which a sensor element is exposed. The protective gas cover has gas inlet holes through which gas to be measured is admitted. The protective cover also has dimples formed adjacent the gas inlet holes, respectively, which are designed to avoid a direct hit of a flow of the gas on the sensor element and minimize the concentration of thermal stress around the gas inlet holes. In an alternative form, the gas inlet holes are formed in the dimples, respectively.

Abstract: Sensor systems and methods are disclosed herein. In general, a sensor can be provided for detecting the presence of a gas (e.g., hydrogen) in an area proximate to the sensor component. A composite material is generally associated with the sensor, wherein the composite material comprises a metal hydride material for gas storage. A heater can also be provided that heats the metal hydride material to a particular temperature at which hydrogen is released from the metal hydride material in order to calibrate and self-test the sensor for detecting the presence of gas.

Abstract: The invention is a system (10) and method for determining a gas composition within a fuel cell (12) of a shut down fuel cell power plant. The system (10) includes at least one fuel cell (12), a sensor circuit (86) secured in electrical connection with the fuel cell (12), wherein the circuit (86) includes a power source (88), a voltage-measuring device (90), and a sensor circuit switch (92). The circuit (86) is secured so that the power source (88) may selectively deliver a pre-determined sensing current to the fuel cell (12) for a pre-determined sensing duration. The system (10) selectively admits the reducing fluid into an anode flow field (28) of the cell (12) whenever the sensor circuit (86) senses that a shut down monitoring voltage of the fuel cell (12) is the same as or exceeds a calibrated sensor voltage limit of the fuel cell (12).

Abstract: The invention is concerned with a method and apparatus for real time analysis of gas mixtures, e g determination of air quality, including at least one resonator (1, 11), means for gas transportation to and from the resonator (1, 11), e g by diffusion or transit flow via openings (5) means for activation (2) and detection (3) of an acoustic signal within the resonator (1, 11), at least one means (7) for measurement of the temperature within the resonator (1, 11), and at least one means (4) for the determination of both the resonance frequency and the quality factor of the resonator (1,11) in real time. These entities are related to the average molecular mass and viscosity or thermal conductivity, respectively, of the gas mixture. The resonator (1, 11 may include a compliant element, e g a constricted volume (6) and an inertial element, e g ist opening (5) or may support standing acoustic waves, in which the sound wavelength is related to a physical dimension of the resonator (1, 11).