Abstract: A gas sensor is used for detecting gas in the air, especially formaldehyde. The sensor comprises at least one gas-sensitive zone which is preferably a layer on a substrate and which contains the ternary compound In4Sn3O12 as the gas-sensitive material. In order to produce the gas-sensitive zone, a flame spray pyrolysis (FSP) is carried out, organometallic compounds of indium and tin being used as the reactants. The gas sensor is especially suitable for online gas detection.

Abstract: Devices, methods and systems for detecting nitro-containing compounds such as TNT, which utilize semiconductor nanostructures modified by a functional moiety that interacts with the nitro-containing compound, are disclosed. The functional moiety is attached to the nanostructures and is being such that upon contacting a sample that contains the nitro-containing compound, the nanostructure exhibits a detectable change in an electrical property, which is indicative of the presence and/or amount of the nitro-containing compound in the sample. Electronic noses for generating recognition patterns of various nitro-containing compounds, made of a plurality of nanostructures modified by versatile functional moieties are also disclosed. The devices, methods and systems are suitable for detecting nitro-containing compounds in both liquid and gaseous states and for detecting a concentration of a nitro-containing compound such as TNT as low as attomolar concentrations.

Abstract: A vehicle brake system. The system includes a wheel brake, a brake pedal, a master cylinder, a first valve, a second valve, a pump, a pressure sensor, a pressure controlling device, and a controller. The master cylinder increases a pressure of a brake fluid in the brake system based on a user depressing the brake pedal. The pump pumps the brake fluid through the first valve to the wheel brake and to draw the brake fluid from the wheel brake through the second valve. The pressure sensor senses a pressure of the brake fluid in the brake system. The pressure controlling device reduces a pressure of the brake fluid at the master cylinder. The controller operates the first and second valves, the pump, and the pressure controlling device during a controlled braking event.

Abstract: A MEMS sensor includes at least one closed nodal anchor along a predetermined closed nodal path on at least one surface of a resonant mass. The resonant mass may be configured to resonate substantially in an in-plane contour mode. Drive and/or sense electrodes may be disposed within a cavity formed at least in part by the resonant mass, the closed nodal anchor, and a substrate.

Abstract: Apparatus for detecting substances in an air sample, the apparatus including: a source of air pressure differential; a cyclone connected to the source of air pressure differential; an air input port connected to the cyclone, to receive the air sample; a substance output port connected to the cyclone, to receive the substances; an input port configured to disperse a finely separated material so that it mixes with said sample; and a detector located at the substance output port, to detect a chemical change in at least one of the substances and the finely separated material.

Abstract: A reliable, low cost device for determining when dangerous levels of hydrogen gas have been generated in a transformer is disclosed. The hydrogen indicator is defined by a module assembly that threads into either the headspace or into the oil-filled body of a transformer. The module has an open interior that contains a film that incorporates a hydrogen-sensitive chemochromic indicator. The indicator film is visible through a lens. When the film has been exposed to hydrogen, chemical changes in the chemochromic indicator cause the film to change color—the color change is immediately visible through the lens.

Abstract: A molecular concentrator comprising a thermal ratchet for driving molecules from one place to another. A plurality of conducting wires are arranged on or suspended above a substrate. Each of the wires is configured to strongly sorb a vapor of interest when the wire is at room temperature and to rapidly desorb the vapor when the wire is at an elevated temperature. By selectively heating and cooling the wires, vapor molecules incident on the wires can be directed in a desired manner, e.g., from the wires closest to the vapor-containing environment to a sensor.

Abstract: The present invention relates to gas sensors using doped ferroelectric materials. The sensors can be fabricated as an array where different portions of the array can operate at different independently controlled temperatures to detect different gas phase components of a gas sample. Preferred embodiments can be used for the diagnosis of conditions, such as, diabetes.

Abstract: A miniature lower cost optical sensing apparatus and method are provided for determining the concentration and/or hazard from a target gas by means of IR or visible photon monitoring one or more sensors that responds to carbon monoxide. The apparatus comprises a photon source optically coupled to the sensor and at least a portion of the photon intensity passing through the sensor is quantified by one or more photodiode(s) in a system, so that the photon flux is a function of at least one sensor's response to the target gas, e.g., transmits light through the sensor to the photodiode. The photo current from the photodiode is converted to a sensor reading value proportional to the optical characteristics of the sensors and is loaded into a microprocessor or other logic circuit. In the microprocessor, the sensor readings may be differentiated to determine the rate of change of the sensor readings and the total photons absorbed value may be used to calculate the CO concentration and/or dose.

Abstract: Provided are methods, devices and systems that utilize free-surface fluidics and SERS for analyte detection with high sensitivity and specificity. The molecules can be airborne agents, including but not limited to explosives, narcotics, hazardous chemicals, or other chemical species. The free-surface fluidic architecture is created using an open microchannel, and exhibits a large surface to volume ratio. The free-surface fluidic interface can filter interferent molecules, while concentrating airborne analyte molecules. The microchannel flow enables controlled aggregation of SERS-active probe particles in the flow, thereby enhancing the detector's sensitivity.

Abstract: A chemical gas sensor formed from a nonwoven material is described. The gas sensor includes a flexible, gas-permeable, nonwoven web-based material substrate having a matrix that is composed of a plurality of inert thermoplastic, pulp, cellulose or staple fibers as either a major or minor portion, with a plurality of gas-sensitive fibers formed from a polymer that can absorb volatile organic compounds (VOC), and a plurality of electrically conductive fibers. The gas-sensitive fibers are intermixed with and associated spatially among a network of adjacent electrically conductive fibers, such that a change in physical morphology of said gas-sensitive fibers as a result of interacting with volatile organic compounds, causes a change in dielectric properties that disrupts said network of adjacent electrically conductive fibers. The sensor can be configured as either a resistive or a capacitive chemisensor.

Abstract: A method and apparatus for detecting a gas in electrical equipment by coupling a gas detection device to the electrical equipment is provided. The method includes providing an electro-magnetic source, positioning an electro-magnetic detector to receive light emitted from the electro-magnetic source, and positioning a membrane between the electro-magnetic source and the electro-magnetic detector, such that the electro-magnetic detector only receives light from the electro-magnetic source that has been transmitted through the membrane. The method also includes detecting at least one gas, such that detection of at least one gas includes preventing or allowing communication of the electro-magnetic source and the electro-magnetic detector, and emitting a signal, by the electro-magnetic detector, in response to the detection of the at least one gas.

Abstract: Disclosed is a sensor for detecting explosive devices. The sensor includes a ferromagnetic metal and a molecular recognition reagent coupled to the ferromagnetic metal. The molecular recognition reagent is operable to expand upon absorption of vapor from an explosive material such that the molecular recognition reagent changes a tensile stress upon the ferromagnetic metal. The explosive device is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

Abstract: Hydrogen sensor including a substrate (S) on which there is deposited an active layer of material comprising a first element selected from the rare earth family, a second element selected from the platinum group metals (PGMs) and a third element selected from the alkaline earth metal family.

Abstract: Provided are a nitric oxide detection element capable of detecting NO gas contained in a mixed gas at a high speed even when the amount thereof is a super trace amount of ten and several parts per billion; and a process for producing the element. In a nitric oxide detection element having a substrate 12 and a sensing film 11 formed on a surface of the substrate, the sensing film is composed of nitric oxide sensing particles and a polymer adhesive. The nitric oxide sensing particles are produced by adsorbing a dye having a porphyrin skeleton and having, as a central metal, divalent cobalt onto surfaces of inorganic particles.

Abstract: A hydrogen detection system can include an exposed detection element made of a catalytic metal which burns hydrogen so as to generate combustion heat. A hydrogen sensor can detect a hydrogen concentration based on a detected value of the detection element. A heating unit can heat the detection element. A hydrogen storage unit is included, and a hydrogen guiding pipe can guide the hydrogen from the hydrogen storage unit to the detection element. A flow rate adjusting device is attached to the hydrogen guiding pipe, and adjusts a flow rate of the hydrogen. A first dilution unit can dilute the hydrogen from the hydrogen storage unit with a dilution gas, and a controller can control the heating unit and the flow rate adjusting device.

Abstract: A chemochromic indicator is provided that includes a hypergolic fuel sensing chemochromic pigment that change from a first color to a second color in the presence of a hypergolic fuel. In a first embodiment, a chemochromic indicator is provided for detecting the presence of a hypergolic fuel such that the irreversible hypergolic fuel sensing chemochromic pigment includes potassium tetrachloroaurate (KAuCl4). There are several types of chemochromic indicators, for example, the article used to form the chemochromic indicators include, but are not limited to, wipe materials, silicone/TEFLON tape, manufactured parts, fabrics, extruded parts, and paints.

Abstract: A fluorescence based sensor (10) is disclosed and described. The sensor (10) can include nanofibril materials (12) fabricated from a linear carbazole oligomer and a fluorescence detector (14). The linear carbazole oligomer can have the formula (I) wherein n is 3 to 9, R are independently selected amine sidegroups, and at least one, but not all, R is a C1 to C14 alkyl. The carbazole-based fluorescence based sensors (10) can be particularly suitable for detection of explosives and volatile nitro compounds.

Abstract: This disclosure relates to the field of molecularly imprinted polymers for detecting target molecules.

Abstract: A chemical indicator having a particulate inorganic substrate, and at least one reactive dye or ink coated on and/or impregnated within the particulate inorganic substrate. Coating and/or impregnating at least one reactive dye or ink on or within a particulate inorganic substrate improves the storage stability and/or thermal stability of the at least one reactive dye or ink, which typically includes relatively unstable compounds. This allows the present indicators to be incorporated into thermoplastic polymer materials and processed conventionally while maintaining the efficacy and stability of the new indicators. The indicators provide simple, reliable, and cost effective detection means for detecting analytes such as ammonia, carbon dioxide, and oxygen, and may find use in applications such as food packaging and medical applications.

Abstract: A chemical pre-concentrator includes a conduit defining a flow path between two ends and having a heating element disposed within the conduit, such that the heating element has at least one sorbent material deposited directly on at least a portion of a conductive surface of the heating element. Some such heating elements are in the form of electrically conductive strips defining both a plurality of apertures through the strip and a series of undulations spaced along the flow path.

Abstract: A vapor generator system (1, 101) for an IMS (4, 104) or other apparatus has a chamber (9, 109) in which vapor is produced. A fan or other flow generator (6, 106) is connected to an inlet (8, 108) of the vapor chamber (9, 109) and its outlet (13, 113) is connected to an adsorbent passage (14, 114), such as formed by a bore through a block (15) of carbon. When the fan (6, 106) is on gas flows through the vapor chamber (9, 109) and the adsorbent passage (14, 114) to the IMS (4, 104) or other outlet, with little vapor being adsorbed in the passage. When the fan (6, 106) is off, any vapor molecules that escape to the adsorbent passage (14, 114) do so at a low rate such that substantially all is adsorbed and no vapor escapes.

Abstract: The invention relates to an apparatus for the determination of a concentration of a component to be measured in a gas, comprising a light source, a wavelength selection unit, a measurement cuvette, a reference cuvette arranged in the optical beam path in parallel thereto, at least one light receiver and an evaluation unit which determines the concentration from the signals of the light receiver, wherein the gas to be analyzed is supplied to the measurement cuvette, on the one hand, and, on the other hand, to the reference cuvette via an absorption apparatus which includes a substance which completely absorbs the component to be measured. Further, the component to be measured is H2S and a wavelength selection unit is provided for the selection of an absorption wavelength.

Abstract: A large volume preconcentrator device for concentrating analytes. A housing accepts an analyte vapor flow, and a plurality of collection surfaces are disposed within the housing. A selectively actuatable heater is disposed on each of the plurality of collection surfaces. At least one selectively actuatable damper is disposed within the housing for selectively restricting a collection flow.

Abstract: Provided herein are explosives detection substrates which include an electrospun (electro)sprayed and/or dry spun aromatic polymer, such as polystyrene, and a small molecule fluorophore. Methods for detecting an explosive material using such substrates are also provided.

Abstract: A gas sensor is disclosed. The gas sensor includes a gas sensing layer, at least one electrode, an adhesion layer, and a response modification layer adjacent to said gas sensing layer and said layer of adhesion. A system having an exhaust system and a gas sensor is also disclosed. A method of fabricating the gas sensor is also disclosed.

Abstract: A sensor, a method for its fabrication, and a method for its use to detect contaminants, for example, ammonia, in stagnant and dynamic fluid media, especially liquid media. The sensor is an opto-chemical sensor that includes a polymer optical fiber, a sensing layer comprising oxazine 170 perchlorate on the polymer optical fiber, and a membrane layer on the sensing layer. The membrane layer is gas permeable and not permeable to the fluid in the fluid system, and moisture is entrapped by and between the sensing and membrane layers.

Abstract: A gas sensor cell using a liquid crystal composite material is provided. The gas sensor cell has recovery capability and can be reused. Upon gas adsorption, the liquid crystal composite material has visually detectable color changes and changes in electrical properties to facilitate the measurement of gas concentration from low to high.

Abstract: A mesoporous, transition metal oxide material having an average pore diameter ranging from 2 to 20 nm, a basic surface character defined by an isoelectric point>pH 7, and a specific surface area greater than 50 m2/g can be incorporated into a NOx sensing device as a NOx film. The mesoporous, transition metal oxide material includes an oxide of yttrium, lanthanum and/or cerium, and can be formed using a surfactant-templated self-assembly process.

Abstract: A portable, relatively low power gas detector incorporates a single pellistor-type sensor for sensing an explosive gas of interest. Outputs from the sensor are corrected in accordance with ambient temperature and humidity and pre-stored correction factors based on characteristics exhibited by a plurality of similar sensors.

Abstract: An apparatus is provided for sensing an analyte in a fluid.

Abstract: A concentration measuring apparatus for hydrogen sulfide includes an absorbing liquid that can absorb gaseous hydrogen sulfide as sulfide ion; a hollow fiber membrane contactor that contacts a gas flow with a flow of the absorbing liquid through a membrane, so that the absorbing liquid absorbs gaseous hydrogen sulfide in the gas flow as sulfide ion; a pump for a first channel that feeds the absorbing liquid to the hollow fiber membrane contactor; an oxidizer that exothermically reacts with sulfide ion; a pump for a second channel that feeds the oxidizer to the absorbing liquid; a first thermometer that measures a temperature of the absorbing liquid before the sulfide ion that the absorbing liquid has absorbed exothermically reacts with the oxidizer; and a second thermometer that measures the temperature of the absorbing liquid after the sulfide ion that the absorbing liquid has absorbed exothermically reacts with the oxidizer.

Abstract: A chemical sensor can include a nanofiber mass of p-type nanofibers having a HOMO level greater than ?5.0 eV. Additionally, the chemical sensor can include oxygen in contact with the p-type nanofibers. Further, the chemical sensor can include a pair of electrodes in electrical contact across the nanofiber mass, where the p-type nanofibers conduct an electric current that decreases upon contact with an amine compound.

Abstract: An instrument to provide on-site analyses utilizing a combination cryotrap and absorbent traps in the extraction of constituents from the sample gas stream consistent with the requirements of 40 CFR Pt. 60 App. A Method 25. The air sample is passed through a cryotrap system which is maintained at the temperature of dry ice ˜72° C.). Heavier molecular weight constituents in the gas sample are condensed on the cold surfaces of the trap. The lighter molecular weight constituents are retained in the absorbent trap, while also acting as a column to separate methane, carbon dioxide, and carbon monoxide from each other and the remain carbon compounds. After separation, all of the sample constituents are oxidized to carbon dioxide and reduced to methane prior to being introduced to a Flame Ionization Detector, which measures the concentration of each against known calibration standards.

Abstract: Methane gas in a ruminant exhalation may be oxidized to reduce the amount of methane gas output by the ruminant.

Abstract: An improved method of extraction, detection, and characterization of a vapor from an explosive, a taggant in an explosive, a controlled substance, a biohazard, and mixtures thereof uses a new and improved SPME device for extraction and ion mobility spectrometry for detection and characterization. The new and improved SPME device has an increased capacity to sorb a target vapor. The increased sorption of vapor provides for more accurate detection by an ion mobility spectrometer. A SPME device having increased surface area may be exposed to an atmosphere in an enclosure containing a test object or a volume of gas that was in contact with the test object to allow for sorption of the target vapor and then introduced into an IMS for more accurate detection and characterization of the vapor due to the increased sorption of the vapor by the SPME device described herein.

Abstract: IMS apparatus has an inlet with a preconcentrator opening into a reaction region where analyte molecules are ionized and passed via a shutter to a drift region for collection and analysis. A pump and filter arrangement supplies a flushing flow of clean gas to the housing in opposition to ion flow. A pressure pulser connects with the housing and is momentarily switched to cause a short drop in pressure, in the housing to draw in a bolus of analyte sample from the preconcentrator. Just prior to admitting a bolus of sample, the pump is turned off so that the flushing flow drops substantially to zero, thereby prolonging the time the analyte molecules spend in the reaction region.

Abstract: A photoluminescent oxygen probe including a tack with a layer of a pressure-sensitive adhesive and an oxygen-sensitive photoluminescent element on the underside of the head. The probe is effective for sensing oxygen concentration within an enclosed space by puncturing the container defining the enclosed space the with the probe's shank and adhering the underside of the probe's head to the container so as to sealingly surround the puncture, thereby placing the oxygen-sensitive photoluminescent dye on the underside of the probe's head into sensible communication with the enclosed space through the puncture hole.

Abstract: The current invention provides a detector and method suitable for sensing vapor-phase hydrogen peroxide. The detector utilizes a chemiluminescent material comprising a peroxide reactive compound, a dye and a solvent. Upon reaction with hydrogen peroxide, the chemiluminescent material will generate detectible light.

Abstract: A device for gas analysis includes a detector tube (2) and can be used in the area of explosive or combustible gases. A filter material, which consists of a granular, porous material and has an impregnation for absorbing toxic gases, is provided between the detector tube (2) and a pump (6).

Abstract: A sensor for detecting hydrogen or ammonia gas uses a gas sensitive material based on Cr2O3 with a small percentage of the chromium replaced by transition metal ions having a valency greater than four, but still having a corundum crystal structure. Electrodes in contact with the gas sensitive material are connected by conductors to electrical measuring means for measuring the resistance, conductance, capacitance, or impedance of the gas sensitive material. A temperature sensing means and heating means allow the temperature of the gas sensitive material to be regulated. The gas sensitive material is formed on an insulator substrate over one or both electrodes. One electrode can be on the non-substrate side of the gas sensitive material. The gas sensitive material can be formed by deposition from a suspension or colloidal dispersion and firing. The gas sensitive material is contacted with gas and changes in electrical properties of the material are observed.

Abstract: A sensor system is formed from a micro machined resonant structure with multiple resonant elements, a tracking resonator control electronics, and signal processing algorithms. The moving elements of the resonator are coated with chemically active materials that change mass when exposed to the target chemical resulting in a change in frequency or period of oscillation. The changes in frequency or period are processed by multi-sensor chemical detection algorithms to identify chemical types and concentrations. In essence, the resonator and drive electronics form a closed loop oscillator operating at the resonator's natural frequency. The resonators are formed from silicon using photolithographic processes. The resonator design includes in-plane resonant motion combined with dynamic balance to operate with a high Q even in the presence of atmospheric pressure.

Abstract: An electronic nose device is disclosed in an embodiment of the invention. The electronic nose device includes a fan module, a gas molecule sensor module, a control unit and an output unit. The fan module is used to pump air actively to the gas molecule sensor module. The gas molecule sensor module detects the air pumped into by the fan module. The gas molecule sensor module at least includes a gas molecule sensor which is covered with a compound. The compound is used to combine preset gas molecules. The control unit controls the fan module to suck air into the electronic nose device. Then the fan module transmits an air current to the gas molecule sensor module to generate a detected data. The output unit calculates the detected data to generate a calculation result and outputs an indicating signal to an operator or compatible host computer according to the calculation result.

Abstract: The invention relates to a humidity sensor including, as a humidity absorbent layer, a polymer layer including a blend including a first polyamide and a second polyamide, where the said second polyamide includes, in its repetitive units, a number of carbon atoms greater than that of the repetitive units of the first polyamide.

Abstract: A sulfur dioxide sensor comprising a first beam having a functionalized sensing surface capable of sensing sulfur dioxide, the first beam capable of producing a first resonant frequency; and a second beam having a functionalized reference surface not capable of sensing sulfur dioxide, the second beam capable of producing a second resonant frequency, wherein differential sensing of sulfur dioxide may be performed, further wherein the first beam is functionalized with a liquid phase of a first polymeric compound and the second beam is functionalized with a liquid phase of a second polymeric compound is provided. In one embodiment, the sensor is a nano-sensor capable of low drift accurately detecting sulfur dioxide levels at the zeptograms level. Methods of making and using a sulfur dioxide sensor are also provided.

Abstract: A molecularly imprinted polymer denuder sensor that includes a trapping solution; a delivery device transporting the trapping solution; a denuder operatively connected to the trapping solution and contacting ambient air, wherein the denuder infuses the sample into the trapping solution; a molecularly imprinted polymer sensor operatively connected to the denuder, wherein the MIP sensor captures and detects the threat material; an excitation source operatively connected to the MIP sensor and having an excitation band, wherein the excitation band excites europium (or other signal transducing lanthanide or metal ion) in the MIP when it is bound to the threat material providing unique emission band(s); and an analytical device operatively connected to the MIP sensor, wherein the analytical device senses the presence of the threat material in the sample.

Abstract: An optical hydrogen gas detecting membrane is prepared by sequentially depositing a platinum oxide layer and a catalytic metal layer on a transparent substrate, such as quartz glass, by vapor deposition such as the sputtering method. Palladium or platinum is used as the catalytic metal layer.

Abstract: A (H2) sensor composition includes a gas permeable matrix material intermixed and encapsulating at least one chemochromic pigment. The chemochromic pigment produces a detectable change in color of the overall sensor composition in the presence of H2 gas. The matrix material provides high H2 permeability, which permits fast permeation of H2 gas. In one embodiment, the chemochromic pigment comprises PdO/TiO2. The sensor can be embodied as a two layer structure with the gas permeable matrix material intermixed with the chemochromic pigment in one layer and a second layer which provides a support or overcoat layer.

Abstract: A gas sensor is provided. The gas sensor includes a gas-sensitive layer which changes in its characteristic properties upon contact with a detectable gas. The gas-sensitive layer has as the main sensitive part, a polycrystalline layer composed of a large number of uniform nano-size microcrystal grains which join together in the planar direction.

Abstract: An optical fiber polarimetric chemical sensor for capillary gas chromatography in which a sample fluid is injected into a capillary in the form of a periodic pulse train. Each individual pulse defines a moving polarization coupling zone that affects the polarization state of the light propagating in a birefringent optical waveguide that includes the capillary. The spacing between consecutive coupling zones can be made equal to the polarization beat length of the waveguide when the injection frequency of the pulses is properly selected, thus defining a resonance condition for a given analyte. The contributions of the successive coupling zones present along the length of the capillary then add up in phase, thus resulting in a detected optical signal having an enhanced amplitude peak at the injection frequency. In this manner, the sensitivity can be enhanced.