4325results about "Gas analyser construction details" patented technology

A method and apparatus for improving measurement accuracy in a gas monitoring system is provided. The apparatus can be connected to a plurality of gas sample lines each containing a gas sample. The gas samples are routed through a number of delivery channels which are fewer in number than the plurality of sample lines. Each delivery channel is alternatively coupled to a detector which identifies contaminants present in the gas samples. Each delivery channel includes a voltage sensitive orifice (VSO). The VSO's are operated by a controller and provide gas samples at a constant flow and a constant pressure to the detector independent of the length of the gas sample line being measured.

A gas sensor system is provided, comprising: a gas cell operable so as to receive a sample gas; a vacuum system fluidically coupled to the gas cell operable to maintain the sample gas within the gas cell at a sub-ambient pressure; a pressure sensor operable to sense a pressure of the sample gas; a thermally insulated enclosure having the gas cell therein; a heat source or heat exchanger operable to influence an interior temperature of the thermally insulated enclosure; a light source within the thermally insulated enclosure operable to provide a mid-infrared (mid-IR) light into and through the gas cell; a photodetector within the thermally insulated enclosure operable to receive the attenuated mid-IR; and a control system electronically coupled to the vacuum system and to the pressure sensor operable to maintain the sample gas within the gas cell at the predetermined pressure to within one torr (1 Torr).

An electronic system and method for detecting analytes, such as carbon dioxide, is provided, using an improved nanostructure sensor (CO2 sensor). The CO2 sensor may comprise a substrate and a nanostructure, such as a one or more carbon nanotubes disposed over the substrate (e.g., as a network). One or more conductive elements may electrically communicate with the nanostructure. A counter or gate electrode may be positioned adjacent the nanostructure. A functionalization material reactive with carbon dioxide may be included, either disposed in contact with the nanostructure or isolated by a dielectric. The sensor may be connected to a circuit responsive to changes in CO2 concentration in the environment. Embodiments are described of medical sensing systems including one or more CO2 sensors. One embodiment comprises a breath sampling cannula which is connected to a sensor unit. In an alternative, the cannula permits supplemental oxygen to be administered, while recovering and measuring analytes in breath samples. The cannula may connect to a portable processor-display unit for monitoring one or more analytes, such as CO2. Another embodiment includes a cannula configured for the monitoring of sleep disorders, such as apnea, comprising one or more sensors disposed adjacent a breath sampling channel, optionally including flow rate or other sensors. The sensors may be connected by wired or wireless links for to a processor / input / display unit. Any of the embodiments may include filters, selectively permeable membranes, absorbents, and the like to precondition the breath sample, may be configured to include complementary chemistry measurements.

Sensors and detection systems suitable for measuring analytes, such as biomolecule, organic and inorganic species, including environmentally and medically relevant volatiles and gases, such as NO, NO2, CO2, NH3, H2, CO and the like, are provided. Certain embodiments of nanostructured sensor systems are configured for measurement of medically important gases in breath. Applications include the measurement of endogenous nitric oxide (NO) in breath, such as for the monitoring or diagnosis of asthma and other pulmonary conditions.

A new sensing technology for chemical / biomolecular sensors is provided. One such sensor detects molecular hydrogen (H2) using nanoelectronic components. A tiny, low-cost nanosensor chip can offer: (i) performance that matches or exceeds that of existing technology, (ii) plug-and-play simplicity with both digital and analog control systems, and (ii) the small size and low power consumption needed for wireless integration.

A computer-implemented system and method for converting the resistances of an array of metal oxide sensors into constituents and concentrations of a multi-component gas provided around the sensor array. The method includes preprocessing the resistances of the sensor array; selecting a model that calculates the constituents and concentrations of the multi-component gas based on the preprocessed resistances; and post-processing the constituents and concentrations of the multi-component gas generated by the selected model to provide the actual constituents and concentrations of the multi-component gas.

Catalysts comprised of at least one catalytically active element and at least one helper catalyst are disclosed. The catalysts may be used to increase the rate, the selectivity or lower the overpotential of chemical reactions. These catalysts may be useful for a variety of chemical reactions including in particular the electrochemical conversion of carbon dioxide to formic acid.

An electronic system and method for detecting carbon dioxide is provided, using a nanostructure sensing device (CO2 sensor). The CO2 sensor is made up of a substrate and a nanostructure disposed over the substrate. The nanostructure may comprise a carbon nanotube, or a network of nanotubes. Two conductive elements are disposed over the substrate and electrically connected to the nanotube. A gate electrode may be positioned opposite the nanostructure. A functionalization material reactive with carbon dioxide is disposed on CO2 sensor, and in particular, on the nanotube. The CO2 sensor may be connected to an electrical circuit, which will respond to changes in CO2 concentration in the ambient sensor environment.

This invention provides ways to fabricate nanotubes and nanobead arrays by utilizing nanopores in anodic aluminum oxide (AAO) membranes. Nanotubes of bismuth and other low melting point metals with controlled diameters and lengths can be fabricated by sintering AAO coated with appropriate metals at temperatures above their melting points. Carbon nanotubes may also be readily formed by carbonizing a polymer on the interior walls of the nanopores in AAO membranes. Palladium nanobead arrays which can be used as ultrafast hydrogen sensors are fabricated by coating the flat surface of AAO membranes with controlled pore-wall ratios.

A vapor sensing device that is sufficiently small and lightweight to be handheld, and also modular so as to allow the device to be conveniently adapted for use in sensing the presence and concentration of a wide variety of specified vapors. The device provides these benefits using a sensor module that incorporates a sample chamber and a plurality of sensors located on a chip releasably carried within or adjacent to the sample chamber. Optionally, the sensor module can be configured to be releasably plugged into a receptacle formed in the device. Vapors are directed to pass through the sample chamber, whereupon the sensors provide a distinct combination of electrical signals in response to each. The sensors of the sensor module can take the form of chemically sensitive resistors having resistances that vary according to the identity and concentration of an adjacent vapor. These chemically sensitive resistors can each be connected in series with a reference resistor, between a reference voltage and ground, such that an analog signal is established for each chemically sensitive resistor. The resulting analog signals are supplied to an analog-to-digital converter, to produce corresponding digital signals. These digital signals are appropriately analyzed for vapor identification. The device can then subsequently transmit the digital signals over a computer network, such as the Internet, for analysis at a remote location.

The self-calibrating carbon monoxide detector and method of the present invention utilize the gas for which the detector was designed to detect as the calibration gas. Specifically, a carbon monoxide gas generator is included in the detector assembly, and is controller to produce a known amount of CO. The sensor response to the quantity of CO generated is monitored, and the calibration thereof adjusted as necessary. The operation of the gas generator is also monitored, and any failures are flagged for user attention. The gas generator specifically suppresses the generation of hydrogen through the materials used in its construction. Temperature effects may also be compensated either through control of gas generation control parameters or compensation of the sensor output in view of the generator temperature effects.

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. Consequently, the conductivity of the nanowires of the sensor and / or switch increases in the presence of hydrogen

A vapor sensing device that is sufficiently small and lightweight to be handheld, and also modular so as to allow the device to be conveniently adapted for use in sensing the presence and concentration of a wide variety of specified vapors. The device provides these benefits using a sensor module that incorporates a sample chamber and a plurality of sensors located on a chip releasably carried within or adjacent to the sample chamber. Optionally, the sensor module can be configured to be releasably plugged into a receptacle formed in the device. Vapors are directed to pass through the sample chamber, whereupon the sensors provide a distinct combination of electrical signals in response to each. The sensors of the sensor module can take the form of chemically sensitive resistors having resistances that vary according to the identity and concentration of an adjacent vapor. These chemically sensitive resistors can each be connected in series with a reference resistor, between a reference voltage and ground, such that an analog signal is established for each chemically sensitive resistor. The resulting analog signals are supplied to an analog-to-digital converter, to produce corresponding digital signals. These digital signals are appropriately analyzed for vapor identification.

A gas sensor determines the presence of at least one designated gas in a gaseous environment. The gas sensor comprises a semiconductor substrate; a thin insulator layer disposed on the semiconductor substrate; a catalytic metallic gate disposed on the thin insulator layer; and a chemically modified layer disposed on the catalytic metal gate. The chemically modified layer comprises a material that protects the sensor from corrosive gases and interference from at least one foreign matter and water, alters at least one of surface chemical properties and surface physical properties of the sensor, and passes only the designated gas therethrough.

A vapor sensing device that is sufficiently small and lightweight to be handheld, and also modular so as to allow the device to be conveniently adapted for use in sensing the presence and concentration of a wide variety of specified vapors. The device provides these benefits using a sensor module that incorporates a sample chamber and a plurality of sensors located on a chip releasably carried within or adjacent to the sample chamber. Optionally, the sensor module can be configured to be releasably plugged into a receptacle formed in the device. Vapors are directed to pass through the sample chamber, whereupon the sensors provide a distinct combination of electrical signals in response to each. The sensors of the sensor module can take the form of chemically sensitive resistors having resistances that vary according to the identity and concentration of an adjacent vapor. These chemically sensitive resistors can each be connected in series with a reference resistor, between a reference voltage and ground, such that an analog signal is established for each chemically sensitive resistor. The resulting analog signals are supplied to an analog-to-digital converter, to produce corresponding digital signals. These digital signals are appropriately analyzed for vapor identification. The device can then subsequently transmit the digital signals over a computer network, such as the Internet, for analysis at a remote location.

A carbon oxide sensor having high sensitivity capable of reduction of influence of humidity is provided. A detection electrode and a counter electrode are provided on one side of an electrolyte, respectively. The detection electrode contains a metal oxide and a metal carbonate including plural components. The metal carbonate preferably contains a first component of alkali metal carbonate and a second component of at least one element selected from the group consisting of alkali earth metal carbonate, transition metal carbonate, zinc carbonate, cadmium carbonate, indium carbonate, lead carbonate and bismuth carbonate. Specifically, it is preferable to contain the first component including Li2CO3 and the second component including at least one element selected from the group consisting of BaCO3, CaCO3 and SrCO3.

A gas measurement system of this invention 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.

To provide a gas sensor and a method of sensing the gas concentrations which are capable of a battery drive through low power consumption and highly reliable, the gas sensor in which an electromotive force type gas sensor element is formed on a substrate, wherein the electromotive force type gas sensor element has a heating element formed on the substrate, a layer of solid electrolyte formed with an insulating layer interposed on the heating element and two electrodes formed on the solid electrolyte and is characterized in that the substrate is a heat-resistant glass base substrate.

An electrochemical gas sensor, a method for making the sensor and methods for the detection of a gaseous species. The electrochemical gas sensor is a solid-state gas sensor that includes a solid polymer electrolyte. A working electrode is separated from a counter electrode by the solid polymer electrolyte. The sensor can include a multilaminate structure for improved detection properties, where electrode microbands are disposed within the solid polymer electrolyte.

A chemical vapor sensor is provided that passively measures a suspect chemical species of interest with high sensitivity and chemical specificity, for use with safety systems. A vapor concentrator amplifies a suspect chemical vapor concentration to a detectible level, for use with an infrared detector. Compensation is provided for environmental variations that may influence the passive measurement of the chemical vapor sensor. Environmental variations may include extrinsic vapors in the surrounding air, or air currents that divert the sample vapor as it drifts from the suspect vapor source to a sampling intake. In an example, ethanol vapor is measured and carbon dioxide tracer measurements are used to calculate an ethanol vapor measurement that is adjusted for environmental variations. In an aspect, a time artifact filter sets the output of the carbon dioxide sensor to match the time dependence of the ethanol sensor, to calculate blood alcohol concentration.

A system for the detection of nitric oxide in a gas sample includes a converter for oxidation of nitric oxide to nitrogen dioxide, a nitrogen dioxide sensor including nanostructures and a filtering device to remove at least carbon dioxide from the gas sample positioned upstream of the converter. The nitrogen dioxide sensor can, for example, include a recognition layer on the nanostructures adapted to enhance sensitivity to nitrogen dioxide. A method for detecting nitric oxide in exhaled breath includes detecting nitric oxide in the exhaled breath using a nitric oxide sensor including nanostructures. Another method for detecting nitric oxide in exhaled breath includes filtering the breath to remove at least carbon dioxide from the breath, oxidizing nitric oxide in the exhaled breath to nitrogen dioxide and detecting the nitrogen dioxide using a nitrogen dioxide sensor including nanostructures.

An interface for coupling a fluid distribution component to a substrate, the interface including an opening therein for receiving at least a portion of the distribution component, the interface including at least one entering pathway and at least one exiting pathway engaging the opening and providing fluid communication between the fluid distribution component and the substrate. The coupling arrangements of the present invention provide a means by which distribution components, such as gas sensors, of various manufacturer designs may be interchangeable.

A method and system for monitoring a flexible pipe, including an inline sensor system coupled to the annulus of the flexible pipe to detect corrosion of the flexible pipe. Also disclosed are method and system for monitoring an amount of water being accumulated in an annulus of a flexible pipe, including locating a pressure measurement system proximate to the annulus for measuring pressure of gas inside the annulus; controlling a flow of vent gas with a vent gas valve; positioning a flow measurement system upstream or downstream of the vent gas valve for measuring the flow of the vent gas when the vent gas valve is opened; and collecting with a microprocessor pressure and flow measurement data from the pressure and the flow measurement systems for determining the amount of water accumulated in the annulus based on the collected pressure and flow measurement data.

A nanoelectronic device includes a nanostructure, such as a nanotube or network of nanotubes, disposed on a substrate. Nanoparticles are disposed on or adjacent to the nanostructure so as to operatively effect the electrical properties of the nanostructure. The nanoparticles may be composed of metals, metal oxides, or salts, and nanoparticles composed of different materials may be present. The amount of nanoparticles may be controlled to preserve semiconductive properties of the nanostructure, and the substrate immediately adjacent to the nanostructure may remain substantially free of nanoparticles. A method for fabricating the device includes electrodeposition of the nanoparticles using one or more solutions of dissolved ions while providing an electric current to the nanostructures but not to the surrounding substrate.

A safety system for connection to a toxic gas detector and a toxic gas producing engine, and its operating method, includes an interrupt device coupled to connections to the detector and the engine. The interrupt device includes a toxic gas signal detecting circuit and a circuit for permitting starting of the engine. The detecting circuit activates the permitting circuit if the toxic gas signal represents a toxic gas concentration below a predetermined level. In one embodiment, the permitting circuit is activated if the safety system is healthy and fully functional.Similarly, a safety system for connection to a toxic gas detector and a toxic gas supply, and its operating method, includes an interrupt device coupled to connections to the detector and the toxic gas supply. The interrupt device includes a toxic gas signal detecting circuit and a circuit for permitting of flow from the toxic gas supply. The detecting circuit activates the permitting circuit if the toxic gas signal represents a toxic gas concentration below a predetermined level.

A mobile device which senses particulate matter is provided. The mobile device includes a housing having an air flow path through which air flows when the mobile device is shaken; an inertia sensor that detects acceleration of the mobile device; a light-scattering type sensor that irradiates the air flow path with light and detects particulate matter in air flowing through the air flow path; and a controller that includes a counter for counting the particulate matter detected by the light-scattering type sensor, and a flow rate calculator for detecting an air flow rate of the air flow path based on a detection signal of the inertia sensor.