Gas Sensing Electrode Patents (Class 204/431)
  • Patent number: 7258773
    Abstract: An oxygen sensor includes a solid polymer electrolyte, e.g., on an acid treated Nafion membrane and uses a diffusion-limited fuel cell type reactions. The sensor avoids electrolyte leakage and avoids consumption of electrodes. In different configurations, a counter or reference electrode can be on the same or the opposite side of the electrolyte as a sensing electrode. An insert limits and controls oxygen diffusion into a sensing chamber containing the sensing electrode that catalyzes reduction of oxygen. Applying appropriate bias voltages to the reference and sensing electrodes causes an output current of the sensing electrode to be proportional to the rate of oxygen consumption based on Frick's law under a diffusion-limited mode. The output current can be measured, e.g., using a resistor to convert the current to a voltage signal.
    Type: Grant
    Filed: August 12, 2003
    Date of Patent: August 21, 2007
    Assignee: RAE Systems, Inc.
    Inventors: Huafang Zhou, Hong T. Sun, Peter C. Hsi
  • Patent number: 7254986
    Abstract: A multi-gas sensor device for the detection of dissolved hydrocarbon gases in oil-filled electrical equipment. The device comprising a semiconductor substrate, one or more catalytic metal gate-electrodes deposited on the surface of the semiconductor substrate operable for sensing various gases, and an ohmic contact deposited on the surface of the semiconductor substrate. The semiconductor substrate comprises one of GaN, SiC, AlN, lnN, AlGaN, InGaN and AlInGaN. A method for sensing gas in an oil-filled reservoir of electrical equipment, comprising providing a sensor device, immersing the sensor device in the oil-filled reservoir, allowing the gases emitted from the oil to interact with the one or more catalytic metal gate-electrodes, altering the gas as it contacts the catalytic metal gate-electrodes and altering the sensitivity of the sensor.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: August 14, 2007
    Assignee: General Electric Company
    Inventors: Edward B. Stokes, Peter M. Sandvik, Vinayak Tilak, Jeffrey B. Fedison, Elena Babes-Dornea, Renyan Qin, James W. Rose, Stanton E. Weaver
  • Patent number: 7201831
    Abstract: There is provided a sample preparation device and method for preparing a sample of liquid for detection of impurities. First (40) and second (38) electrodes are provided, located for immersion in a liquid under test. A semipermeable membrane (42) is positioned to protect the first electrode (40) from a body of liquid under test (32). The semipermeable membrane allows the liquid under test to pass therethrough to reach the first electrode, while preventing solids carried in the liquid from reaching the first electrode, the first electrode being positioned to affect the liquid under test in the vicinity of a sensor (36). Particular embodiments feature a hydrophilic membrane to protect the electrodes from suspended solids in the sample, a thin electrode assembly to achieve a faster response and the addition of a heater for temperature control to achieve consistent detection conditions and improved anti-fouling properties.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: April 10, 2007
    Assignee: Water Security and Technology, Inc.
    Inventor: David Robert Vincent
  • Patent number: 7182846
    Abstract: A gas sensor element is provided which is designed to measure the concentration of hydrogen-containing gas accurately. The sensor element includes an oxygen pump cell working to keep the concentration of oxygen contained in measurement gasses entering a measurement gas chamber at a low concentration level and a hydrogen-containing gas measurement cell. The hydrogen-containing gas measurement cell is made up of a proton-conductive solid electrolyte body and a first and a second gas measurement electrode affixed to the proton-conductive solid electrolyte body. The first gas measurement electrode is exposed to the measurement gas chamber and serves to produce a signal between the first and second gas measurement electrodes as a function of the concentration of the hydrogen-containing gas.
    Type: Grant
    Filed: May 29, 2003
    Date of Patent: February 27, 2007
    Assignees: Denso Corporation, Nippon Soken, Inc.
    Inventors: Keigo Mizutani, Masataka Naito, Daisuke Makino, Kazunori Suzuki
  • Patent number: 7182845
    Abstract: An electronic sensing circuit for an electrochemical gas sensor cell providing high dynamic range is described. The electronic circuit utilizes an amplifier with a resistive feedback element to provide high sensitivity linear sensing of low detected gas concentrations. The electronic circuit also provides the ability to source sufficient current to prevent the electrochemical gas sensor cell from becoming biased under very high gas concentration conditions. This operation is enabled by adding a non-linear element in the feedback path of the amplifier, which non-linear element begins to conduct during the high gas concentration conditions.
    Type: Grant
    Filed: October 15, 2004
    Date of Patent: February 27, 2007
    Assignee: Ranco Incorporated of Delaware
    Inventor: Timothy D. Kaiser
  • Patent number: 7179355
    Abstract: Disclosed is an electrochemical sensor for measuring carbon monoxide in a gas sample, the sensor comprising a working electrode including a working electrode catalyst, and a diffusion restriction means for restricting the diffusion of the gas sample to the working electrode; wherein the working electrode catalyst comprises oxidised platinum having a hydrogen cross-sensitivity of less than 10% and being present in an amount such that the activity capacity is at least 5.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: February 20, 2007
    Assignee: Alphasense Limited
    Inventor: John Christopher Harper
  • Patent number: 7175753
    Abstract: A process and a device are provided for monitoring the hydrogen concentration in a gas with at least one device, which comprises an electrochemical gas sensor and a bipotentiostat, e.g., for use in internal combustion engines with hydrogen, in fuel cells and in the petrochemical industry. The electrochemical gas sensor used has two working electrodes (3) and (4), with which the hydrogen and oxygen concentrations are determined in the gas in different steps due to the application of a voltage by a bipotentiostat (5-18). In an additional, optional step, a voltage in the range of ?1,100 mV to ?800 mV is applied to a working electrode (4), so that hydrogen is formed at the working electrode (4) and the functional surface of the working electrode (4) as well as the sensitivity of the working electrode (3) to hydrogen can be checked.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: February 13, 2007
    Assignee: Drägerwerk Aktiengesellschaft
    Inventors: Herbert Kiesele, Peter Tschuncky
  • Patent number: 7168295
    Abstract: A gas sensor has a sensor element inserted in a cylindrical housing. A measured gas cover, provided at a distal end side of the housing, forms a measured gas environment at a distal end side of the sensor element. An atmospheric air cover, provided at a proximal end side of the housing, forms an atmospheric air environment at a proximal end side of the sensor element. A clearance between an inside surface of the housing and an outside surface of the sensor element is gastightly sealed with a sealing member including a plurality of powder filler layers to separate or isolate the measured gas environment from the atmospheric air environment.
    Type: Grant
    Filed: March 28, 2005
    Date of Patent: January 30, 2007
    Assignee: Denso Corporation
    Inventors: Masanobu Yamauchi, Motoaki Satou, Kiyomi Kobayashi
  • Patent number: 7160422
    Abstract: A multilayered gas sensing element 2 is positioned in a cylindrical housing 10 via a cylindrical insulator 3. The multilayered gas sensing element 2 includes a narrow-width portion 21 and a wide-width portion 22. The wide-width portion 22 is in a fixed relationship with respect to the insulator 3. The narrow-width portion 21 is in a floating relationship with respect to the insulator 3. The narrow-width portion 21 has a gas sensing portion for detecting the concentration of a specific gas contained in a measuring objective gas.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: January 9, 2007
    Assignee: Denso Corporation
    Inventors: Shinichiro Imamura, Susumu Naito, Makoto Nakae, Namitsugu Fujii
  • Patent number: 7156968
    Abstract: An electrode comprises a catalyst and material to help stabilize an oxide of the catalyst. The electrode for one embodiment may be used for an electrochemical sensor or sensor cell.
    Type: Grant
    Filed: May 9, 2003
    Date of Patent: January 2, 2007
    Assignee: MST Technology GmbH
    Inventors: Serguei Tsapakh, Kathrin Keller, Andreas Röhrl
  • Patent number: 7144553
    Abstract: Chemical sensors for detecting the activity of a molecule or analyte of interest is provided. The chemical sensors comprise and array or plurality of sensors that are capable of interacting with a molecule of interest, wherein the interaction provides a response fingerprint. The fingerprint can be associated with a library of similar molecules of interest to determine the molecule's activity and diffusion coefficient.
    Type: Grant
    Filed: August 29, 2003
    Date of Patent: December 5, 2006
    Assignee: The California Institute of Technology
    Inventors: Nathan S. Lewis, Erik J. Severin, Michael Freund, Adam J. Matzger
  • Patent number: 7109563
    Abstract: Systems, devices and methods are provided to improve performance of integrated circuits by providing a low-k insulator. One aspect is an integrated circuit insulator structure that includes a vapor-deposited dielectric material. The dielectric material has a predetermined microstructure formed using a glancing angle deposition (GLAD) process. The microstructure includes columnar structures that provide a porous dielectric material. One aspect is a method of forming a low-k insulator structure. In one embodiment, a predetermined vapor flux incidence angle ? is set with respect to a normal vector for a substrate surface so as to promote a dielectric microstructure with individual columnar structures. Vapor deposition and substrate motion are coordinated so as to form columnar structures in a predetermined shape. Other aspects are provided herein.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: September 19, 2006
    Assignee: Micron Technology, Inc.
    Inventors: Kie Y. Ahn, Leonard Forbes
  • Patent number: 7110887
    Abstract: A residual chlorine meter detects a pre-calibration residual chlorine reaction amount of sample water in a detection section, inputs a calibration standard residual chlorine standard concentration of the sample water in an input section, determines calibration factors from data for computing the calibration factors based on the amount and the concentration stored in a calibration factor computation data storage section in a calibration factor computation section, and stores the calibration factors in a calibration factor storage section.
    Type: Grant
    Filed: October 20, 2004
    Date of Patent: September 19, 2006
    Assignee: Tanita Corporation
    Inventors: Shinichi Harima, Kiyoshi Sagawa
  • Patent number: 7087150
    Abstract: A chloramine amperometric sensor includes a sensor body with an electrolyte disposed inside the sensor body. A membrane is coupled to the sensor body and adapted to pass chloramine therethrough. A reference electrode is disposed in the electrolyte and coupled to a first conductor. A second conductor is coupled to a working electrode that is disposed proximate the membrane. The working electrode is constructed from a noble metal in non-compact form. The non-compact form can be a Gas Diffusion Electrode, which can include metal mesh, carbon paper, carbon cloth, metal/carbon powder loaded on a porous membrane or any combination thereof.
    Type: Grant
    Filed: May 3, 2002
    Date of Patent: August 8, 2006
    Assignee: Rosemount Analytical Inc.
    Inventor: Chang-Dong Feng
  • Patent number: 7077938
    Abstract: The present invention relates to an electrochemical gas sensor that includes a first planar substrate having at least one planar electrode formed thereon, thereby forming a first electrode assembly, and a housing defining a reservoir which, in use, contains liquid electrolyte for contacting the electrode(s). The housing has a first sealing face to which the first electrode assembly is sealed, the sealing face having conducting portions electrically isolated one from another. A portion of at least one electrode is in contact with a respective conducting portion so as to provide a means of external electrical connection to the electrode(s). The conductive portions and non-conductive portions of the housing are co-moulded. This sensor has a relatively small number of component parts and is relatively cheap and easy to manufacture. It also provides a cheap and reliable way of forming external electrical connections to the electrodes.
    Type: Grant
    Filed: October 26, 2000
    Date of Patent: July 18, 2006
    Assignee: Invensys Controls UK Limited
    Inventors: Malcolm Trayton Austen, John Robert Dodgson
  • Patent number: 7074319
    Abstract: One embodiment of an ammonia gas sensor includes: a reference electrode, an ammonia selective sensing electrode and an electrolyte disposed therebetween. The sensing electrode comprises the reaction product of a main material selected from the group consisting of vanadium, tungsten, molybdenum, vanadium oxides, tungsten oxides, molybdenum oxides, and combinations comprising at least one of the foregoing main materials, and an electrically conducting material selected from the group consisting of electrically conductive metals, electrically conductive metal oxides, and combinations comprising at least one of the foregoing.
    Type: Grant
    Filed: December 11, 2003
    Date of Patent: July 11, 2006
    Assignee: Delphi Technologies, Inc.
    Inventors: Da Yu Wang, Walter T. Symons, Robert J. Farhat, Carlos A. Valdes, Elizabeth M. Briggs, Kaius K. Polikarpus, Joachim Kupe
  • Patent number: 7060169
    Abstract: An electrochemical cell for applications such as electrochemical fuel cells, or electrochemical cell gas sensors used for detection of target gas species in environments containing or susceptible to presence of same. The electrochemical cell utilizes an ionic liquid as an electrolyte medium, thereby achieving a broader range of operational temperatures and conditions, relative to electrochemical cells utilizing propylene carbonate or other conventional electrolytic media.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: June 13, 2006
    Assignee: MST Technology GmbH
    Inventor: Andreas Röhrl
  • Patent number: 7045046
    Abstract: The invention relates to a sensor adapted for electrical connection to a power source having an electrical contact means (3). The sensor has a first insulating substrate (1) carrying a first electrode (2) and a second insulating substrate (7) carrying a second electrode (6). The electrodes are disposed to face each other in spaced apart relationship, sandwiching a spacer (4) therebetween. A first cut-out portion extends through the first insulating substrate (1) and a spacer (4) to expose a first contact area (23) on the second insulating substrate (7). This permits the electrical contact means (31) to effect electrical connection with the first contact (23) which in turn is in electrically conductive connection with the second electrode (6). A similar contact arrangement may be disposed on the opposite side of the sensor.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: May 16, 2006
    Assignee: LifeScan, Inc.
    Inventors: Garry Chambers, Alastair McIndoe Hodges, Thomas William Beck, Ian Andrew Maxwell
  • Patent number: 7013707
    Abstract: The invention includes a method and apparatus for a chromatography system having a chromatographic column for separating gases in a mixture from one another and an electrochemical gas sensor coupled to the chromatographic column for detecting a gas being emitted from the column. The electrochemical gas sensor further includes a substrate having a surface for depositing electrodes thereon, an ionomer membrane in contact with the surface, an electrode in contact with the surface, and an opening in the ionomer membrane in a location proximate to the electrode for permitting a gas to diffuse through the opening to simultaneously contact the electrode and the ionomer membrane within the opening.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: March 21, 2006
    Assignee: PerkinElmer LAS, Inc
    Inventors: Otto J. Prohaska, Avinash Dalmia, Andrew Tipler
  • Patent number: 6940287
    Abstract: An unheated planar sensor element for determining the concentration of a gas component in a gas mixture, in particular the oxygen concentration in the exhaust gas of an internal combustion engine, has a sensor foil made of a solid electrolyte with an outer electrode exposed to the measuring gas, and an inner electrode exposed to a reference gas, as well as a reference-gas channel, which is covered by the sensor foil on one side and accommodates the inner electrode. To produce a small-volume, cost-effective unheated sensor element for use in small combustion engines having low power output yet sufficiently satisfactory measuring accuracy, the reference-gas channel is sealed on the underside by an additional sensor foil made of a solid electrolyte, and covered by an inner electrode lying inside the reference-gas channel and an outer electrode exposed to the measuring gas.
    Type: Grant
    Filed: March 10, 2004
    Date of Patent: September 6, 2005
    Assignee: Robert Bosch GmbH
    Inventors: Helmut Weyl, Jens Schneider, Detlef Heimann, Thomas Wahl, Hans-Joerg Renz, Norman Hahn, James Richard Waldrop, II, Damien Barnes, Mike McCormick, John Day
  • Patent number: 6929728
    Abstract: The invention relates to a sensor for measuring a gas concentration or ion concentration which has a substrate (11), a drain (3) formed on the substrate, a source (2) formed on the substrate, a channel area (4) of the substrate located between drain (3) and source (2), a conductive guard ring (1) located outside the channel area, and a sensitive gate layer (8) whose potential depends on the surrounding gas or ion concentration, with an air gap (10) provided between the gate layer and channel area (4). In order to create a sensor that can be made economically and compactly which nevertheless ensures exact measurement of a change in concentration with time, it is provided that surface profiling (7 and 12) be formed between guard ring (1) and channel area (4).
    Type: Grant
    Filed: April 12, 2002
    Date of Patent: August 16, 2005
    Assignee: Micronas GmbH
    Inventor: Heinz-Peter Frerichs
  • Patent number: 6913731
    Abstract: Intended for application on ducts through which flow a fluid at a high temperature, and particularly at a high pressure, comprising two bodies (4) and (8) which axially screw onto each other, one body (4) provided with a threaded neck (5) for attachment to the orifice of duct wall (3), which body (4) houses within it sensor element (2) of the probe which is thus placed inside the duct, with second body (8) screwed onto first body (4) and exerting on sensor element (2) the pressure required to secure it in its housing, with second body (8) further provided with an axial orifice through which passes a metallic tube (9) open to the exterior and which is provided with a metallic washer (10), soldered to said tube (9), which is separated from second body (8) by an electrically insulating washer (12).
    Type: Grant
    Filed: February 8, 2002
    Date of Patent: July 5, 2005
    Assignee: Union Fenosa Generacion, S.A.
    Inventors: José Manuel Bueno Harto, Francisco Javier Perosanz Lopez
  • Patent number: 6908538
    Abstract: The invention relates to an electrochemical gas sensor having improved response time and sensitivity. The electrochemical gas sensor includes a substrate for providing a surface upon which an electrode may be placed, a first electrode placed on the surface, a thin film of electrolyte support for receiving electrolyte and having a predetermined porosity, and a second electrode deposited on the thin film for permitting a measurement of current between the first and second electrodes.
    Type: Grant
    Filed: October 22, 2001
    Date of Patent: June 21, 2005
    Assignee: PerkinElmer Instruments LLC
    Inventors: Avinash Dalmia, Otto J. Prohaska
  • Patent number: 6908536
    Abstract: A digital electrochemical sensor is provided with a sensor electrode array (1-4) and an operating electronic unit integrated on a chip for processing electrical signals received therefrom. The operating electronic unit includes a potentiostat circuit and a microprocessor, which receives and further processes the signals processed by the operating electronic unit. To provide an electrochemical sensor which can be operated more simply and with higher precision during installation and in operation the potentiostat circuit is a digital circuit, whose controller function is controlled by the microprocessor (20), and for the microprocessor (20) to be also integrated on the chip of the operating electronic unit.
    Type: Grant
    Filed: December 12, 2001
    Date of Patent: June 21, 2005
    Assignee: Drägerwerk Aktiengesellschaft
    Inventor: Udo Beckmann
  • Patent number: 6849168
    Abstract: An electrochemical microsensor package comprises a substrate matrix having a upper non-conductive layer and an adjacent lower non-conductive layer with a conductive trace or pad extending over an area therebetween. The conductive pad has integral therewith a projecting contact button that projects through and below the second non-conductive for making contact with external electrical contacts. A sensor electrode is positioned on the surface of the conductive pad toward the upper non-conductive layer and in electrical contact therewith. A well extends through the upper non-conductive layer to the upper surface of the electrode. The microsensor packages may be produced by electrodeposition of the conductive pad onto a conductive mandrel having depressions to form the contact button.
    Type: Grant
    Filed: November 9, 2001
    Date of Patent: February 1, 2005
    Assignee: KVAL, Inc.
    Inventors: William F. Crumly, Marc J. Madou
  • Patent number: 6841387
    Abstract: The invention comprises novel apparatuses and testing methods for evaluating a fluid diffusion component. The apparatus includes a fluid capable of undergoing oxidation or reduction, a half-cell electrode assembly able to receive the fluid, and a change in acidity indicator in communication with the assembly. An inventive method of the invention includes the steps of passing a fluid capable of undergoing oxidation or reduction through a half-cell electrode assembly to form a sample, contacting the sample with an indicator, and detecting a change in acidity in the indicator.
    Type: Grant
    Filed: August 21, 2002
    Date of Patent: January 11, 2005
    Assignee: Advanced Energy Technology Inc.
    Inventor: David M. Kaschak
  • Patent number: 6841053
    Abstract: An electronic tongue for the detection of ozone is based on voltammetry, and comprises at least one working electrode and a counter electrode, wherein the working electrode(s) is(are) made of one or more transition metals or Au, or alloys thereof, or alloys thereof with other metals. The data processing is made by multivariate analysis. The sensor can be implemented on-line or in-line in a processing plant where it is desirable to monitor and control ozone levels, e.g. sterilization and purification plants.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: January 11, 2005
    Assignee: Otre AB
    Inventors: Fredrik Winquist, Carina Högberg, Christina Krantz-Rückler, Kjell Ekberg
  • Patent number: 6837987
    Abstract: A method and apparatus for detecting the presence of carbon monoxide in a gas which may also contain contaminating substances uses a pre-treatment means to absorb contaminating substances and to convert them to non-contaminating substances.
    Type: Grant
    Filed: June 15, 2000
    Date of Patent: January 4, 2005
    Assignee: Dart Sensors Limited
    Inventor: Walter John King
  • Publication number: 20040231984
    Abstract: The present invention relates to planar electrochemical sensors with membrane coatings used to perform chemical analyses. The object of this invention is to provide unit-use disposable sensors of very simple and inexpensive construction, preferably with only a single membrane coating on an electrode. The invented devices are potentiometric salt-bridge reference electrodes and dissolved gas sensors constructed with a heterogeneous membrane coating of a conductor. The heterogeneous membrane, which is an intimate admixture of a hydrophobic and a hydrophilic compartment, concurrently supports constrained transport of non-volatile species through its hydrophilic compartment and rapid gas and water vapor transport through its hydrophobic compartment.
    Type: Application
    Filed: June 1, 2004
    Publication date: November 25, 2004
    Inventors: Imants Lauks, Anca Varlan, Alexandra Oussova, Michael Bales
  • Patent number: 6808618
    Abstract: In an improved amperometric gas sensor, the structure, composition, and electrode potential are adjusted so as to prevent or minimize any unwanted reactivity at the counter and/or reference electrode of any analyte or interfering component of the matrix that may cross over thereto. The sensor is preferably structured so that the product of the analyte reaction at a first working electrode can be reconverted to the original analyte at a counter electrode or at a second working electrode and then reacted again at the first working electrode, with such back-and-forth reactions repeating many times, so as to yield an amplification of the analyte signal.
    Type: Grant
    Filed: July 25, 2001
    Date of Patent: October 26, 2004
    Inventor: Joseph Robert Stetter
  • Patent number: 6808619
    Abstract: In an electrode system, particularly for electrochemical sensors, which comprises a working electrode, a counterelectrode and an electrolyte, the counterelectrode is constituted by a material containing an elementary carbon, whereby the long-term stability of the electrode system is considerably increased (FIG. 2).
    Type: Grant
    Filed: May 17, 2001
    Date of Patent: October 26, 2004
    Assignee: Roche Diagnostics Operations, Inc.
    Inventor: Helmut Offenbacher
  • Publication number: 20040188250
    Abstract: A gas concentration sensor includes a sensor element consisting of a pump cell, a monitor cell, and a sensor cell. These cells are heated by a heater and maintained in an activated condition. A sensor control unit measures a weak element current flowing in a sensor element in accordance with the concentration of a specific gas component and intermittently supplies electric power to the heater. The sensor control unit is electrically connected via electric cables to the gas concentration sensor. The weak element current cables and the heater cable are banded together. The electric cables have a shielding layer that is provided outside a core wire through which the element current flows and is fixed to the ground potential.
    Type: Application
    Filed: March 22, 2004
    Publication date: September 30, 2004
    Applicant: DENSO CORPORATION
    Inventors: Hiroyuki Sakai, Yoshikazu Hatada, Takashi Kojima
  • Publication number: 20040168914
    Abstract: An automotive lambda oxygen sensor is formed by electroless plating of a thin, catalytically active, conductive electrode uniformly on the outer surface of a zirconia thimble. The process includes forming a pristine zirconia solid electrolyte thimble and drilling out a cylindrical cavity in it. A porous outer surface suitable for producing crystallization sites is formed by dipping the unfired thimble in a zirconia slurry containing spray-dried microspheres and firing the coated thimble to densify the thimble and the microspheres and to produce cavities on the surface of the thimble. An inner platinum electrode is formed by conventional conductive ink painting on the axial cavity of the sensor, and the sensor is again fired. The surface is activated by immersion in an acetone chloroplatinic acid bath to form multiple crystallization points, heat treated, then plated in an electroless platinum bath to a desired thickness.
    Type: Application
    Filed: February 27, 2004
    Publication date: September 2, 2004
    Inventors: Mary R. Reidmeyer, Matthew J. Donelon, Robert F. Killion
  • Publication number: 20040168913
    Abstract: An ionisation detector includes a third (fence) electrode (55) between the counter electrode (53) and the sensing electrode (54). The fence electrode (53) is maintained at or near the potential of the sensing electrode (54) and traps charge movement (electrolytic current) along the detector walls associated with condensation and/or contamination within the detector. In a photoionisation detector, the fence electrode is also adapted to trap photo-induced current originating from the cathode (53).
    Type: Application
    Filed: December 4, 2003
    Publication date: September 2, 2004
    Inventors: William Francis Houlton Dean, Mark Julian Stockdale
  • Publication number: 20040154920
    Abstract: A contamination-resistant sensor element and methods for making the same are provided. A sensor element may include a contamination-resistant coating on at least a portion thereof. The coating may comprise gamma-delta alumina and lithium oxide and may have a thickness of about 100 to about 600 microns and a porosity of about 20 to about 70 percent. The method may include using gamma-delta alumina and lithium oxide to form a mixture, applying the mixture to at least a portion of a sensor element, and temperature treated the mixture to form a contamination-resistant coating on the surface of the measuring cell.
    Type: Application
    Filed: February 10, 2003
    Publication date: August 12, 2004
    Applicant: Robert Bosch Corporation
    Inventors: Jens Stefan Schneider, James Richard Waldrop, Velma Viane Massey, Donald Stanley Frost
  • Patent number: 6773577
    Abstract: A method is provided for detecting imminent failure of an electrochemical cell, such as an electrochemical oxygen sensor, including detecting the presence of a gas pocket in/over the electrolyte within the cell either optically, by differences in the path of a light beam through the cell, due to the different refractive indices of air or nitrogen gas and electrolyte solutions or electrically, by loss of electrolyte between a pair of electrodes. An electrochemical cell assembly also is provided having a gas pocket detection assembly. Lastly, a method for retrofitting an electrochemical cell with a gas pocket detection assembly also is provided, along with a kit for retrofitting a cell with a gas pocket detection assembly.
    Type: Grant
    Filed: September 19, 2001
    Date of Patent: August 10, 2004
    Assignee: Teledyne Technologies Incorporated
    Inventors: Stephen H. Broy, Michael A. Gonzalez, Mann Nguyen
  • Publication number: 20040149579
    Abstract: A method and apparatus for monitoring and measuring gas concentrations in combustor applications is provided, wherein the apparatus is a gas sensor having a plurality of electrodes cooperating with a single electrolyte cell for detecting the presence and concentration of gaseous components of a flue gas. A voltage is generated based on the flow of ions caused by differing gas concentrations as detected by electrodes across the electrolyte. The change in voltage is correlated and is used to determine the concentration of detected gases, such as combustible gases, nitric oxides, carbon monoxide, etc., contained in the flue gas. The combustor operation may then be optimized to enhance efficiency and minimize undesired gas concentrations in the flue gas in a desired fashion. A calibration gas may be introduced to calibrate the apparatus and a reference gas may be provided to an electrode as a basis for correlating the concentrations of the gases.
    Type: Application
    Filed: December 18, 2003
    Publication date: August 5, 2004
    Applicant: General Electric Company
    Inventors: Carl A. Palmer, Eric Weissman, Earl Goodsell, Dominic T. Flauto, Jeff Parmelee, Donald A. Schneider, Jeff Johanning
  • Patent number: 6758962
    Abstract: Oxygen concentration measurement is carried out over a broad range by an instrument utilizing a zinc-air cell having a lower-than-nominal potential difference imposed across its electrodes by a shunt branch incorporating the source-drain circuit of a field effect transistor (FET). A feedback circuit is used to improve linearity of the output and cell life without sacrificing the broad dynamic range achieved by the use of the FET shunt branch.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: July 6, 2004
    Assignee: Doxs Technology Systems, Inc.
    Inventors: Matthew S. Fitzgerald, Edward C. Berdich, Peter M. Draper
  • Patent number: 6759010
    Abstract: Chemical sensors for detecting the activity of a molecule or analyte of interest is provided. The chemical sensors comprise and array or plurality of sensors that are capable of interacting with a molecule of interest, wherein the interaction provides a response fingerprint. The fingerprint can be associated with a library of similar molecules of interest to determine the molecule's activity and diffusion coefficient.
    Type: Grant
    Filed: July 20, 2001
    Date of Patent: July 6, 2004
    Assignee: California Institute of Technology
    Inventors: Nathan S. Lewis, Erik J. Severin, Michael Freund, Adam J. Matzger
  • Patent number: 6752964
    Abstract: This invention relates to a novel class of vapor sensors with tunable properties. More particularly, this invention relates to vapor sensors modified by the addition of a compatible small molecule of low volatility, i.e., a plasticizer. In certain aspects, the invention relates to a sensor for detecting an analyte in a fluid comprising: an organic polymer; a plasticizer combined with the organic polymer; and detector operatively associated with the organic polymer.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: June 22, 2004
    Assignee: California Institute of Technology
    Inventors: Robert H. Grubbs, Nathan S. Lewis, Adam J. Matzger
  • Publication number: 20040112744
    Abstract: A hydrocarbon sensor is formed with an electrolyte body having a first electrolyte surface with a reference electrode depending therefrom and a metal oxide electrode body contained within the electrolyte body and having a first electrode surface coplanar with the first electrolyte surface. The sensor was formed by forming a sintered metal-oxide electrode body and placing the metal-oxide electrode body within an electrolyte powder. The electrolyte powder with the metal-oxide electrode body was pressed to form a pressed electrolyte body containing the metal-oxide electrode body. The electrolyte was removed from an electrolyte surface above the metal-oxide electrode body to expose a metal-oxide electrode surface that is coplanar with the electrolyte surface. The electrolyte body and the metal-oxide electrode body were then sintered to form the hydrocarbon sensor.
    Type: Application
    Filed: November 25, 2003
    Publication date: June 17, 2004
    Inventors: Rangachary Mukundan, Eric L. Brosha, Fernando Garzon
  • Patent number: 6746583
    Abstract: There is provided a microchip-based differential-type carbon dioxide gas sensor for detecting dissolved carbon dioxide levels. It functions with at least one working electrode composed of an unbuffered hydrogel membrane containing a certain amount of sodium bicarbonate and a pH-sensitive gas-permeable membrane; and a reference electrode composed of a buffered hydrogel membrane and a pH-sensitive gas-permeable membrane. The unbuffered hydrogel membrane contains carbonic anhydrase, which reduces the time period for the hydration of carbon dioxide, thereby allowing the quick measurement of the level of carbon dioxide. In addition to being significantly improved in stabilization, sensing, and recovering time periods, the differential-type carbon dioxide gas sensor can be fabricated in small sizes and quickly measure levels of carbon dioxide dissolved in sample solution.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: June 8, 2004
    Assignee: i-Sens, Inc.
    Inventors: Jae Seon Lee, Jae Ho Shin, Min Hyung Lee, Hakhyun Nam, Geun Sig Cha
  • Patent number: 6740225
    Abstract: A thick film electrochemical microsensor device for measuring or regulating chlorine and bromine in water, comprising a substrate to which is applied an optimum arrangement of at least two electrodes. The device is especially useful for measuring or regulating chlorine and bromine levels in swimming pool or spa water. A method of measuring or regulating ions of at least one of chlorine and bromine in water is also described, which comprises contacting the water with the microsensor of the present invention; measuring the current output of the microsensor; determining the level of at least one of chlorine and bromine indicated by the current output; and generating a signal.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: May 25, 2004
    Assignee: Hathaway Brown School
    Inventors: Bonnie Gurry, Meijun Shao, Laurie Dudik, Chung-Chiun Liu
  • Publication number: 20040084303
    Abstract: An electrochemical device (18) for generating a desired gas of the type includes an ionically conductive electrolyte layer (20), a porous electrode layer (22), and a current collector layer (16) that has a high electrical conductivity and is porous to a desired gas (24) generated by the electrochemical device (18). The current collector layer (16) is substantially formed as a film comprised of a layer of spherical refractory material objects (26) having a conductive coating (12) of a precious metal. The coated spherical objects (26) have a desired diameter (28) making them suitable for forming into the film.
    Type: Application
    Filed: December 2, 2002
    Publication date: May 6, 2004
    Applicant: Litton Systems, Inc.
    Inventors: Scott R. Sehlin, Courtney J. Monzyk
  • Publication number: 20040079637
    Abstract: Electrolytic solution which contains sulfuric acid and is stored in an electrolytic solution storage 2 of a case 3 is caused to be retained in an electrolytic solution retainer 25. A reference electrode 18 and a counter electrode 19 are printed on the underside of the electrolytic solution retainer 25. The reference electrode 18, the counter electrode 19, and the electrolytic solution retainer 25 are thus formed into a single component, with the reference electrode 18 and the counter electrode 19 being formed simultaneously. Electrode pins 32,33,34 are brought into contact with the reference electrode 18, the counter electrode 19, and a detection electrode 17. The electrode pins 32,33,34 are made of tantalum. A contact portion 32b,33b,34b and a lead portion 32a,33a,34a of each electrode pin 32,33,34 are formed as a seamless, integral body.
    Type: Application
    Filed: September 29, 2003
    Publication date: April 29, 2004
    Inventors: Tatsuo Maeno, Hiromi Nakano
  • Publication number: 20040069627
    Abstract: A sensor includes a metallic housing having a hollow portion, a metallic terminal pin, a part of which is inserted into the hollow portion of the housing, a sensing element connected to the terminal pin, and a resin casing. The terminal pin and the resin casing provide a connector for connecting an outer circuit outside the sensor. A part of the resin casing is disposed in the hollow portion. The terminal pin and the housing are molded with the resin casing by insert molding so that the resin casing, the terminal pin, and the housing are integrated together.
    Type: Application
    Filed: August 22, 2003
    Publication date: April 15, 2004
    Inventor: Teruo Oda
  • Patent number: 6719950
    Abstract: An exhaust gas sensor includes a housing and a sensor element supported by the housing. The sensor element includes a support member having an exhaust side, a reference side, and an aperture extending through the support member between the exhaust side and the reference side. The sensor element further includes an exhaust-side electrode on the exhaust side of the support member. The exhaust-side electrode is electrically connected to a contact on the reference side of the support member via a lead extending through the aperture. The aperture is sealed around the lead such that gas cannot pass through the aperture. The support member is oriented substantially parallel to the flow of exhaust gases when the exhaust gas sensor is installed on a vehicle. The sensor further includes a contact pin in the housing that engages the contact and biases the sensor element against a portion of the housing.
    Type: Grant
    Filed: November 14, 2001
    Date of Patent: April 13, 2004
    Assignee: Robert Bosch Corporation
    Inventors: John Day, Jens Stefan Schneider, Harald Neumann, Heinrich Hipp
  • Publication number: 20040055900
    Abstract: An apparatus 20 may include a generator 22 and a combustion turbine 24 for driving the generator, the combustion turbine having an air inlet 40 for receiving an inlet air flow. The apparatus may also include an inlet air flow sampling sensor 26. The inlet air flow sampling sensor 26, in turn, may include a solution container 46 for containing a solution 50 for sampled air from the inlet air flow. The inlet air flow sampling sensor 26 additionally may include sensing circuitry for sensing at least one dissolved material in the solution 50. For example, the material may be salt, such as found in the inlet air for coastal power plants.
    Type: Application
    Filed: September 23, 2002
    Publication date: March 25, 2004
    Applicant: Siemens Westinghouse Power Corporation
    Inventors: Eugene E. Smeltzer, Brian D. Ottinger, Mary Anne Alvin
  • Publication number: 20040055899
    Abstract: Disclosed herein is a method of improving a chemo/electro-active material by increasing the sensitivity of the material; increasing the stability of an electrical response characteristic of the chemo/electro-active material; or increasing the speed with which a change in an electrical response characteristic of the chemo/electro-active material is detected.
    Type: Application
    Filed: April 15, 2003
    Publication date: March 25, 2004
    Inventors: Patricia A. Morris, John Carl Steichen, J.J. Barnes, Charles E. Miller, Eugene Michael McCarron
  • Publication number: 20040050718
    Abstract: A method for determining the quantity and identity of an electrochemically convertible substance in a gas sample. The substance is converted in an electrochemical sensor producing an electrical output. The characteristic parameters of a curve-defining equation y(t)=k×(e−axt−e−bxt) are calculated based on three measurements of output at times t, 2t and 4t. The integral under all or part of the curve is calculated to determine the quantity of the substance. The equation parameters are compared with standard values to determine the identity of the substance.
    Type: Application
    Filed: July 21, 2003
    Publication date: March 18, 2004
    Applicant: Lifeloc Technologies, Inc.
    Inventor: Frank A. Traylor