With Gas Diffusion Electrode Patents (Class 204/432)
  • Patent number: 7615139
    Abstract: An electrochemical sensor with at least one measuring electrode (3), at least one auxiliary electrode (7) and at least one reference electrode (5), wherein a protective electrode (6), which ensures at the reference electrode (5) the at least partial shielding of the reference electrode (5) against substances that would lead to a change in the reference potential when reaching the reference electrode (5), is arranged in the vicinity of the reference electrode (5). A highly stable reference potential can be obtained with the present invention.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: November 10, 2009
    Assignee: Dräger Safety AG & Co. KGaA
    Inventors: Herbert Kiesele, Frank Mett, Sabrina Sommer
  • Publication number: 20090272648
    Abstract: An electrochemical gas detector includes a superhydrophobic, nanostructured gas porous electrode. The electrode exhibits a physically disrupted porous region. In an embodiment, electrode material can be deposited around a templating material which is removed before use. Such electrodes exhibit repeatable and reproducible characteristics.
    Type: Application
    Filed: April 28, 2009
    Publication date: November 5, 2009
    Inventor: Keith Francis Edwin Pratt
  • Patent number: 7600507
    Abstract: An exhaust sensor control system for an exhaust sensor is mounted in an exhaust path of an internal combustion engine, wherein the exhaust sensor includes a sensor element for generating an output in accordance with the status of an exhaust gas and a heater for heating the sensor element. The exhaust sensor control system includes a recovery value counting means, a heater control means, a cumulative lean time counting means, and a determination value correction means.
    Type: Grant
    Filed: March 4, 2009
    Date of Patent: October 13, 2009
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Keiichiro Aoki
  • Patent number: 7601250
    Abstract: A miniaturized gas sensor comprised of thick- or thin-film type electrodes, on a non-conductive supportive substrate, and in contact with a solid ionomer electrolyte, for the detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive substrate. The electrodes are discrete and in intimate contact with the same solid polymer ionomer membrane. The sensor cell contains no liquid electrolyte and is operated in a constant-voltage, potentiostatic or potentiodynamic mode. A high sensitivity to a select gas or vapor is achieved by a novel three-phase contact area design for a sensing electrode which provides contact with the solid ionomer electrolyte, as well as the gas sample via diffusion openings or holes that penetrate through the supportive substrate.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: October 13, 2009
    Assignee: PerkinElmer LAS, Inc.
    Inventors: Otto J. Prohaska, Anthony B. LaConti, Jose D. Giner, Mourad Manoukian
  • Patent number: 7541192
    Abstract: A process is provided for distinguishing between wet from dry gas with a breath alcohol measuring device, in which a defined sample volume from a gas blown in is fed for sampling to an electrochemical sensor (6), which generates a sensor signal that depends on the reaction of ethyl alcohol. The sensor signal is sent to a control and evaluating unit (4) and is evaluated there to determine the alcohol concentration. To distinguish dry gas from wet gas, provisions are made for the sensor signal to be detected in its time dependence and for the presence of wet gas to be determined when it is observed that a sensor signal of a polarity opposite the polarity of the sensor signal caused by the reaction of ethyl alcohol appeared at first at the beginning of sampling. The process may be used, e.g., in conjunction with the calibration of breath alcohol measuring devices or in so-called interlock systems with a breath alcohol measuring device in order to recognize attempts at manipulation.
    Type: Grant
    Filed: July 14, 2005
    Date of Patent: June 2, 2009
    Assignee: Dräger Safety AG & Co. KGaA
    Inventor: Burkhard Stock
  • Patent number: 7534333
    Abstract: An electrochemical gas sensor which comprises an electrode assembly, including a catalytic sensing electrode and a counter electrode, mounted inside a housing provided with at least one gas entrance, a reservoir for containing electrolyte in use, a compressible wick for supplying the electrode assembly with electrolyte and a wick compression component. A first end of the wick extends into the reservoir and a second end of the wick contacts the electrode assembly. The wick compression component compresses the wick in a direction substantially radial to an axis joining its first and second ends.
    Type: Grant
    Filed: May 26, 2005
    Date of Patent: May 19, 2009
    Assignee: City Technology Limited
    Inventors: Peyman Khalafpour, Stuart Christopher Cutler
  • Publication number: 20090057150
    Abstract: An electrochemical gas sensor is disclosed which comprises a gas sensing electrode and a counter electrode disposed within a housing, the housing having an aperture for gas ingress, the gas sensing electrode and counter electrode being separated by a region containing electrolyte, and means for connecting the gas sensing electrode and the counter electrode to a sensing circuit. An electrolyte-absorbing element is disposed inboard of the aperture, between the housing and the gas sensing electrode, in order to absorb electrolyte passing through the gas sensing electrode whilst maintaining a gas path through the electrolyte-absorbing element.
    Type: Application
    Filed: January 9, 2008
    Publication date: March 5, 2009
    Applicant: LIFE SAFETY DISTRIBUTION AG
    Inventors: Andrew Peter MILLAR, Martin Jonathan KELLY
  • Patent number: 7393505
    Abstract: A proton conductor gas sensor whose durability at high temperature is enhanced by using gel not converted to sol even at high temperature in a water reservoir. Fine particles of silica are gelled by adding water thereto and agitating the mixture under shear force. The thus obtained gel (34) is placed in a water reservoir of proton conductor gas sensor (2) and fed through steam introduction port (30) to MEA (10).
    Type: Grant
    Filed: July 28, 2003
    Date of Patent: July 1, 2008
    Assignee: Figaro Engineering Inc.
    Inventors: Tomohiro Inoue, Hideki Okoshi, Kazunari Kaneyasu
  • Publication number: 20080145722
    Abstract: A gas sensor system includes a membrane electrode assembly including a polymer electrolyte membrane and electrode layers disposed on opposing sides of the membrane, where an anode side of the sensor is defined at first side of the assembly and a cathode side of the sensor is defined at a second side of the assembly. The gas sensor is configured to detect a gas in an environment (e.g., a housing, a pipe, an open environment, etc.) by measuring an open circuit voltage between the anode and the cathode sides of the assembly. The gas sensor provides a rapid response that measures gas concentration in the environment and is further durable, reliable and relatively inexpensive to manufacture.
    Type: Application
    Filed: June 25, 2007
    Publication date: June 19, 2008
    Inventors: Philippe A. Coignet, Samuel E. Moore
  • Patent number: 7381314
    Abstract: An aqueous solution of a Na salt of a phenol sulfonic acid polymer as a liquid electrolyte is held in a separator of a liquid electrochemical gas sensor. A sensing electrode and a counter electrode are connected to the separator to detect CO at a range from about ?40° C. to about 70° C.
    Type: Grant
    Filed: March 30, 2005
    Date of Patent: June 3, 2008
    Assignee: Figaro Engineering Inc.
    Inventors: Tomohiro Inoue, Yuki Fujimori
  • Patent number: 7378008
    Abstract: Water is stored in a metal can, and water vapor is supplied to a separator through an opening in a washer. The separator is an alkali metal salt in a sulfonated synthetic resin membrane, and KOH aqueous solution is used as the electrolyte, and the sensing electrode and the counter electrode are Pt—C, and solid proton conductive membranes are placed between the electrodes and the separator.
    Type: Grant
    Filed: January 3, 2005
    Date of Patent: May 27, 2008
    Assignee: Figaro Engineering Inc.
    Inventors: Tomohiro Inoue, Yuki Fujimori
  • Patent number: 7316768
    Abstract: A gas sensor comprises an electrically conductive housing including a shelf member and a chamber containing an electrolyte. A conductive cathode mounted on the shelf member has a plurality of holes therein and a conductive tail element. A gas permeable membrane overlying the cathode prevents electrolyte from escaping the chamber but allows gas to permeate the membrane. An anode within the chamber is in electrical contact with the electrolyte and the conductive housing. The tail element is adapted to be connected to the anode through an electrical circuit including the conductive housing.
    Type: Grant
    Filed: April 29, 2004
    Date of Patent: January 8, 2008
    Assignee: Advanced Micro Instruments, Inc.
    Inventors: Roland Aldridge, Steven Kirchnavy, Hurbert Q. Stedman
  • Patent number: 7279081
    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: Grant
    Filed: September 29, 2003
    Date of Patent: October 9, 2007
    Assignee: Nemoto & Co., Ltd.
    Inventors: Tatsuo Maeno, Hiromi Nakano
  • 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: 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: 7090755
    Abstract: A test signal is applied in parallel with an electrochemical gas sensor for about ten seconds, while an amplifying circuit is turned off. After turning off the test signal, the amplifying circuit is turned on. If the gas sensor outputs an waveform of a predetermined shape in a predetermined period after the turning-on, the gas sensor will be judged to be normal.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: August 15, 2006
    Assignee: Figaro Engineering Inc.
    Inventors: Tomohiro Inoue, Yuki Fujimori
  • 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: 7033482
    Abstract: An electrochemical gas sensor is self-diagnosed on the basis of an output waveform that is generated when a power source of said gas sensor is turned on after said power source has been turned off for a short time and an output waveform that is generated when said power source is turned on after said power source has been turned off for a long time. In a normal gas sensor, when the power source is turned on after the power source has been turned off for the short time, a bottom will be generated in the potential of the sensing electrode side, and when the power source is turned on after the power source has been turned off for the long time, a peak will be generated in the potential of the sensing electrode side. A self-diagnosis of the electrochemical gas sensor can be done without pulse power source for self-diagnosis, and the dead time from self-diagnosis until start of detection can be shortened.
    Type: Grant
    Filed: January 3, 2005
    Date of Patent: April 25, 2006
    Assignee: Figaro Engineering Inc.
    Inventor: Tomohiro Inoue
  • Patent number: 7022213
    Abstract: The invention relates to a gas sensor and its method of manufacture. Electrochemical gas sensors usually comprise an external housing, which acts as a reservoir for electrolyte; a wick to keep electrodes wetted with the electrolyte and external electrical terminals, for making electrical contact with the electrodes. Typically a gas permeable/microporous membrane has been used to seal a gas sensor in order to prevent leakage of electrolyte. A problem with existing sensors has been that there was a risk of electrolyte leaking through the membrane around the region where electrical connectors passed therethrough. The present invention overcomes this by providing a method of urging conductive polymer through the membrane under controlled conditions of heat and pressure, thereby ensuring the integrity of the membrane remains in tact while defining an electrically/conductive pathway therethrough.
    Type: Grant
    Filed: August 24, 2000
    Date of Patent: April 4, 2006
    Assignee: Invensys Controls UK Limited
    Inventors: Malcolm Trayton Austen, John Robert Dodgson
  • Patent number: 6936147
    Abstract: A miniaturized gas sensor comprised of thick- or thin-film type electrodes, on a non-conductive supportive substrate, and in contact with a solid ionomer electrolyte, for the detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive substrate. The electrodes are discrete and in intimate contact with the same solid polymer ionomer membrane. The sensor cell contains no liquid electrolyte and is operated in a constant-voltage, potentiostatic or potentiodynamic mode. A high sensitivity to a select gas or vapor is achieved by a novel three-phase contact area design for a sensing electrode which provides contact with the solid ionomer electrolyte, as well as the gas sample via diffusion openings or holes that penetrate through the supportive substrate.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: August 30, 2005
    Assignee: Perkinelmer Las, Inc.
    Inventors: Otto J. Prohaska, Anthony B. LaConti, Jose D. Giner, Mourad Manoukian
  • 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
  • Publication number: 20040242412
    Abstract: Ruthenium sulfide catalyst and gas diffusion electrodes incorporating the same for reduction of oxygen in industrial electrolyzers which catalyst is highly resistant to corrosion making it useful for oxygen-depolarized aqueous hydrochloric acid electrolysis.
    Type: Application
    Filed: April 22, 2004
    Publication date: December 2, 2004
    Inventors: Andrea F. Gulla, Robert J. Allen, Emory S. De Castro
  • Patent number: 6764582
    Abstract: A gas sensor suitable for measuring hydrogen concentration, including a proton conductive layer (1); a first electrode (3) and a second electrode (5) provided on the proton conductive layer (1); a gas diffusion-limiting inlet (19) provided between the first electrode (3) and a measurement gas atmosphere (6) containing hydrogen gas; and a gas diffusion-limiting outlet (21) provided between the second electrode (5) and the atmosphere (6); wherein the ratio (a/b) between the diffusion resistance (a) of the diffusion limiting portion (19) and the diffusion resistance (b) of the gas outlet portion (21) is not greater than 2.
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: July 20, 2004
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Norihiko Nadanami, Shoji Kitanoya, Tomonori Kondo, Masaya Watanabe, Noboru Ishida
  • 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: 6746587
    Abstract: An electrochemical gas sensor comprises: a working electrode for exposure to a gas to be sensed; a counter electrode having an outer periphery; a reservoir for electrolyte; wick means providing a path for electrolyte to pass from the reservoir, around a first part or parts of the outer periphery of the counter electrode to provide electrolytic continuity between the counter electrode and the working electrode; and a gas diffusion means providing a path for gas to diffuse to or from a second part or parts of the outer periphery of the counter electrode.
    Type: Grant
    Filed: November 15, 2001
    Date of Patent: June 8, 2004
    Assignee: Alphasense Limited
    Inventors: John R. Saffell, Darryl H. Dawson
  • 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
  • Patent number: 6666963
    Abstract: A compact, long-lived oxygen sensor having an aqueous electrolyte and three gas diffusion electrodes, a working electrode, a reference electrode and a counter electrode. A porous, hydrophobic means is employed in conjunction with the counter electrode to allow air pressure in the sensor to be balanced with atmospheric pressure. The working and reference electrodes are further protected from contact with flow of electrolyte from the reservoir by a separator, so that the current output is fairly independent of sensor movement.
    Type: Grant
    Filed: August 14, 2002
    Date of Patent: December 23, 2003
    Assignee: Industrial Scientific Corporation
    Inventors: Wenfeng Peng, P. Richard Warburton
  • Patent number: 6656335
    Abstract: An apparatus for measuring partial hydrogen pressure in a gas stream is described. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: December 2, 2003
    Assignee: General Electric Company
    Inventors: Elena Babes-Dornea, Claude Beauchemin, Renyan Qin, Jean-Christophe Marusic
  • Publication number: 20030209442
    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: Application
    Filed: February 19, 2003
    Publication date: November 13, 2003
    Applicant: Alphsense Limited
    Inventor: John Christopher Harper
  • Patent number: 6638407
    Abstract: An electrochemical sensor having electrolyte, at least two electrodes and an electrolyte reservoir in a housing. The sensor has a hydrophobic gas communication means between said electrodes, electrolyte reservoir and ambient atmosphere. An electrochemical sensor having hydrophobic communication means mounted between electrodes and extending down to the electrolyte reservoir of the electrochemical sensor. Either embodiment of the sensor can provide oxygen for operation of the sensor and a balance of pressure, without interfering or poisonous gases.
    Type: Grant
    Filed: September 13, 2001
    Date of Patent: October 28, 2003
    Assignee: Senco Sensors Inc.
    Inventor: Wenfeng Peng
  • Patent number: 6635160
    Abstract: The invention relates to gas sensors, particularly electrochemical gas sensors. The reliability of such gas sensors has been ascertained by regular tests, which involve exposing a sensor to a gas for test or calibration purposes. However, it has been difficult to provide a known quantity or concentration of gas. Another problem has been that blockage of a gas inlet has rendered the gas sensor unreliable. The invention provides a gas sensor having a self test capability and first and second electrodes, arranged so that test gas arrives at a separate instant at each electrode so as to generate two electric currents, the ratio of which currents provides an indication of the status of at least one electrode.
    Type: Grant
    Filed: December 28, 2001
    Date of Patent: October 21, 2003
    Assignee: Central Research Laboratories Limited
    Inventor: John Dodgson
  • Patent number: 6623619
    Abstract: Electrochemical sensor for determining analyte in the presence of interferent, particularly carbon monoxide in the presence of hydrogen. An electrochemical cell is designed so that current flow resulting from reference electrode potential shift caused by interferent cancels out the current flow caused by interferent at the working electrode. Another electrochemical cell corrects for interferent concentration using the potential difference between a reference electrode in contact with interferent and a referent electrode not affected by inteferent.
    Type: Grant
    Filed: May 14, 2001
    Date of Patent: September 23, 2003
    Assignee: Alphasense Limited
    Inventors: John R Saffell, Michael L Hitchman, Darryl H Dawson
  • Publication number: 20030155239
    Abstract: The invention describes a sensor element for determining the concentration of gas components in gas mixtures, in particular in exhaust gases of combustion engines. It includes at least one measured gas space (13) and at least one gas inlet opening (17) through which the gas mixture is conveyable to the measured gas space (13), and at least one diffusion barrier (12) arranged between the gas inlet opening (17) and measured gas space (13). The diffusion barrier (12) includes at least one layer (14, 14a, 14b) of catalytically active material for establishing equilibrium in the gas mixture.
    Type: Application
    Filed: February 4, 2003
    Publication date: August 21, 2003
    Inventors: Roland Stahl, Gerhard Hoetzel, Harald Neumann, Johann Riegel, Lothar Diehl
  • Publication number: 20030121781
    Abstract: A miniaturized gas sensor comprised of thick- or thin-film type electrodes, on a non-conductive supportive substrate, and in contact with a solid ionomer electrolyte, for the detection of toxic gases, i.e., carbon monoxide, and other oxidizable or reducible gases and vapors is described. The all-solid planar sensor cell has two or more film type electrodes arranged on a non-conductive planar surface of a supportive substrate. The electrodes are discrete and in intimate contact with the same solid polymer ionomer membrane. The sensor cell contains no liquid electrolyte and is operated in a constant-voltage, potentiostatic or potentiodynamic mode. A high sensitivity to a select gas or vapor is achieved by a novel three-phase contact area design for a sensing electrode which provides contact with the solid ionomer electrolyte, as well as the gas sample via diffusion openings or holes that penetrate through the supportive substrate.
    Type: Application
    Filed: November 18, 2002
    Publication date: July 3, 2003
    Inventors: Otto J. Prohaska, Anthony B. LaConti, Jose D. Giner, Mourad Manoukian
  • Patent number: 6584827
    Abstract: An electrochemical gas sensor for detecting a specific gas being measured with a plurality of electrodes (21, 3, 4), an electrolyte (7) and a gas-permeable membrane (9) has a reduced cross sensitivity with respect to interfering gases, a short response time and high sensitivity for the measured gas without the service life being reduced. The measuring electrode is a layer of doped diamond thin (21) on a porous substrate (22), where the gas-permeable memebrane is disposed over the measuring electrode to permit passage therethru of the gas being measured.
    Type: Grant
    Filed: May 16, 2002
    Date of Patent: July 1, 2003
    Assignee: Drägerwerk Aktiengesellschaft
    Inventors: Herbert Kiesele, Frank Mett, Peter Tschuncky
  • Patent number: 6579433
    Abstract: An electrochemical measuring cell for detecting hydrocyanic acid is improved in such a manner that a stable measurement signal is provided after a short time. The measuring cell includes a measuring electrode (1) of sintered gold and a counter electrode (2). A measuring cell housing (4) accommodates the measuring electrode (1) and the counter electrode (2). An electrolyte is in the measuring cell housing (4) and includes sulphuric acid with an additive of silver sulphate. A diffusion membrane (5) is disposed between the measuring electrode (1) and the substance to be detected.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: June 17, 2003
    Assignee: Dräger Safety AG & Co. KGaA
    Inventors: Christoph Bernstein, Andreas Nauber
  • Publication number: 20030106811
    Abstract: The invention relates to a method and apparatus for providing an electrochemical gas sensor having improved response time for detecting a gas introduced into the sensor. The sensor includes a substrate having a first surface and a second surface and an electrode deposited on the first surface. The sensor also includes an ionomer membrane in contact with the first surface and the electrode. The ionomer membrane has an opening in a location proximate to the electrode for permitting gas introduced into the sensor to diffuse through the opening to simultaneously contact the electrode and the ionomer membrane within the opening. The substrate further includes at least one hole extending from the first surface to the second surface for permitting moisture to diffuse through the at least one hole to contact the ionomer membrane for enhancing sensitivity.
    Type: Application
    Filed: January 16, 2003
    Publication date: June 12, 2003
    Inventors: Otto J. Prohaska, Avinash Dalmia
  • Patent number: 6566894
    Abstract: A device and method for detecting oxidizable and/or reducible gases in the air for controlling ventilation plants in buildings or motor vehicles and for monitoring combustion processes or waste gas analysis by a capacitance sensor that detects change in sensor capacities at two different frequencies. Alternating currents having at least two frequencies is passed through a heated sensor between contact electrodes of the sensor and a polycrystalline metal oxide sensor material and an evaluation circuit measures a change in capacitance between the electrodes and sensor material. A change in capacitance measured at a first frequency indicates the presence of reducible gases while a change in sensor capacitance at a second frequency indicates the presence of oxidizable gases. Variations in sensor ohmic resistance at the two frequencies are also considered.
    Type: Grant
    Filed: October 30, 1998
    Date of Patent: May 20, 2003
    Assignee: Rosemarie Brand-Gerhart
    Inventor: Hanns Rump
  • Patent number: 6506296
    Abstract: An apparatus for measuring hydrogen content and partial hydrogen pressure in gas streams and a method of modeling the sensor based on the characteristics of the sensor. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: January 14, 2003
    Assignee: General Electric Company
    Inventors: Elena Babes-Dornea, Claude Beauchemin, Renyan Qin
  • Patent number: 6468407
    Abstract: A sensor is disclosed that comprises an electrolyte disposed between and in intimate contact with a sensing electrode and a reference electrode. A protective coating is disposed on the protective layer adjacent to the sensing electrode. The protective coating comprises a mixture of a metal oxide, a zeolite, and an alumina. A method for making the sensor is also disclosed.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: October 22, 2002
    Assignee: Delphi Technologies, Inc.
    Inventors: Eric P. Clyde, Paul Kikuchi, Richard F. Beckmeyer, William J. LaBarge
  • Publication number: 20020121438
    Abstract: An electrochemical gas sensor comprises: a working electrode for exposure to a gas to be sensed; a counter electrode having an outer periphery; a reservoir for electrolyte; wick means providing a path for electrolyte to pass from the reservoir, around a first part or parts of the outer periphery of the counter electrode to provide electrolytic continuity between the counter electrode and the working electrode; and a gas diffusion means providing a path for gas to diffuse to or from a second part or parts of the outer periphery of the counter electrode.
    Type: Application
    Filed: November 15, 2001
    Publication date: September 5, 2002
    Inventors: John R. Saffell, Darryl H. Dawson
  • Patent number: 6436257
    Abstract: A fuel cell for generating a current in response to the presence of acetylene in a fluid. The fuel cell comprises first and second gas porous electrode means, and acidic electrolyte means interconnecting the first and second electrode means for facilitating the electrochemical oxidation of the acetylene at the first electrode means and the electrochemical reduction of oxygen in an oxygen-containing gas at the second electrode means so as to generate the current, the first electrode means being a gas porous gold electrode means.
    Type: Grant
    Filed: June 9, 1999
    Date of Patent: August 20, 2002
    Assignee: General Electric Company
    Inventors: Elena Babas-Dornea, Bernard Noirhomme
  • Patent number: 6428665
    Abstract: An electrochemical gas sensor has a first gas diffusion electrode for a first reaction gas, which is inactive with respect to a second reaction gas at least in a first potential window, and a second gas diffusion electrode for the second reaction gas, which is active with respect to the second reaction gas at least in a second potential window for measuring two different gases in gas mixtures in a casing. The two gas diffusion electrodes are electronically isolated from one another, but electrically connected electrolytically to a reversibly loadable electrode and have contacts for connecting external closing circuits for adjusting the cell currents. The gas mixture is fed to the gas diffusion electrodes in series or parallel. The casing containing the electrodes is, in particular, in the form of a button cell. The reversibly loadable electrode is a Cu/CuO, Zn/ZnO or hydrogen electrode. The gas diffusion electrodes have a porous structure based on carbon or have a porous silver structure.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: August 6, 2002
    Assignee: Varta Geratebatterie GmbH
    Inventors: Dejan Ilic, Konrad Holl, Joachim Helmke, Hans-Joachim Kohnke, August Winsel
  • Publication number: 20020043458
    Abstract: An electrochemical measuring cell for detecting hydrocyanic acid is improved in such a manner that a stable measurement signal is provided after a short time. The measuring cell includes a measuring electrode (1) of sintered gold and a counter electrode (2). A measuring cell housing (4) accommodates the measuring electrode (1) and the counter electrode (2). An electrolyte is in the measuring cell housing (4) and includes sulphuric acid with an additive of silver sulphate. A diffusion membrane (5) is disposed between the measuring electrode (1) and the substance to be detected.
    Type: Application
    Filed: October 9, 2001
    Publication date: April 18, 2002
    Applicant: Drger Safety AG & Co. KGaA.
    Inventors: Christoph Bernstein, Andreas Nauber
  • Patent number: 6325979
    Abstract: A sensing element, in particular for an electrochemical sensor for determining gas concentrations, having at least one three-dimensional electrode arrangement, applied on a support plate and forming trenches of a depth for measuring changes in capacitance and/or conductivity in a gas-sensitive layer arranged to a height in the trenches, the height of the gas-sensitive layer being less than the depth of the trenches.
    Type: Grant
    Filed: June 7, 1999
    Date of Patent: December 4, 2001
    Assignee: Robert Bosch GmbH
    Inventors: Dieter Hahn, Gottfried Flik, Bernd Schumann
  • Publication number: 20010040104
    Abstract: A modified universal exhaust gas oxygen sensor, referred to herein as a CEGA sensor, is provided which can be used to measure the concentration of a variety of components of a gaseous fuel emission including CO, CO2, O2, H2, and H2O. The CEGA sensor-employs at least one additional electrode on a ceramic substrate which possess a different catalytic activity relative to the electrodes that normally found on a UEGO sensor. The ceramic substrate may be made of any suitable ceramic and is preferably made of zirconia. The difference in catalytic activity between the additional electrode(s) and the electrodes native to the UEGO sensor create an oxygen gradient which enables a measure of combustion completeness to be calculated. In combination with an air/fuel ratio measured by the sensor, the concentrations of different components in the emission can be calculated.
    Type: Application
    Filed: March 27, 2001
    Publication date: November 15, 2001
    Inventors: Ronald S. Patrick, Fabio DeAmicis
  • Publication number: 20010032789
    Abstract: An apparatus for measuring partial hydrogen pressure in a gas stream is described. The apparatus includes a housing with micro-fuel cell sensor disposed therein. The sensor includes a sensing element having first and second gas diffusing electrodes spaced from one another with an acidic electrolyte disposed between the electrodes. A first gas permeable membrane separates the first electrode from an external gas stream. A second gas permeable membrane separates the second electrode from atmospheric air. Electrochemical charging of the first electrode occurs when hydrogen from a gas stream diffuses through the first membrane to react with the first electrode, while the potential of the second electrode remains unchanged. The potential difference between the first and second electrodes measured as current is identified to represent the sensor output.
    Type: Application
    Filed: February 28, 2001
    Publication date: October 25, 2001
    Inventors: Elena Babes-Dornea, Claude Beauchemin, Renyan Qin, Jean-Christophe Marusic
  • Patent number: 6303018
    Abstract: A method for determining relative amounts of O2 and N2O in gas mixtures by quantitative electrochemical reaction including feeding a gas mixture containing O2 and N2O to a zinc-air cell having electrodes connected to a circuit consisting of a plurality of diodes and resistors, which circuit is set to have an electrochemical working range corresponding to each of the O2 and N2O; and measuring current flowing in the respective working range to determine the relative proportions of O2 and N2O in the gas mixture. An electrochemical cell including a casing capable of containing a gas mixture, including O2 and N2O a zinc-air cell in the casing, and a circuit connected to electrodes of the zinc-air cell, the circuit containing a plurality of diodes, resistors and tap points; means for measuring current to determine the relative proportions of O2 and N2O in the gas mixture.
    Type: Grant
    Filed: October 13, 1999
    Date of Patent: October 16, 2001
    Assignee: Varta Geratebatterie GmbH
    Inventors: Konrad Holl, Dejan Ilic, Michael Schmalz, Hans-Joachim Kohnke
  • Patent number: RE38931
    Abstract: A method for measuring a target constituent of an electroplating solution using an electroanalytical technique is set forth in which the electroplating solution includes one or more constituents whose by-products skew an initial electrical response to an energy input of the electroanalytical technique. The method comprises a first step in which an electroanalytical measurement cycle of the target constituent is initiated by providing an energy input to a pair of electrodes disposed in the electroplating solution. The energy input to the pair of electrodes is provided for at least a predetermined time period corresponding to a time period in which the electroanalytical measurement cycle reaches a steady-state condition. In a subsequent step, an electroanalytical measurement of the energy output of the electroanalytical technique is taken after the electroanalytical measurement cycle has reached the steady-state condition.
    Type: Grant
    Filed: February 27, 2003
    Date of Patent: January 10, 2006
    Assignee: Semitool, Inc.
    Inventors: Lyndon W. Graham, Thomas C. Taylor, Thomas L. Ritzdorf, Fredrick A. Lindberg, Bradley C. Carpenter