Abstract: A gas sensor is provided for detecting one or more gases in a gas sample. The gas sensor includes a substrate, a solid electrolyte layer including lanthanum oxide for sensing carbon dioxide, a heating element thermally coupled to the solid electrolyte layer, and a controller coupled to the heating element and the solid electrolyte layer. The controller heats the heating element so that the solid electrolyte layer reaches an operating. Methods of sensing carbon dioxide and humidity are also disclosed.

Abstract: A sensor for detecting a target substance, in particular carbon dioxide, in a gas stream comprises a sensing element (8) disposed to be exposed to the gas stream, the sensing element comprising a working electrode (12); a counter electrode (14); and a solid electrolyte precursor (16) extending between and in contact with the working electrode and the counter electrode; whereby the gas stream may be caused to impinge upon the solid electrolyte precursor such that water vapour in the gas stream at least partially hydrates the precursor to form an electrolyte in electrical contact with the working electrode and the counter electrode.

Abstract: In an oxygen sensor for installation in the exhaust gas system of a vehicle for detecting a concentration of NOx in exhaust gas downstream from a catalytic converter, in which the exhaust gas is passed through a protective layer to an electrode disposed at one side of a solid electrolyte in a sensor element of the oxygen sensor, the protective layer is formed with a combination of values of thickness and porosity which provide improved sensitivity in detecting low levels of NOx in the exhaust gas.

Abstract: A method for pumping a sealed internal reference chamber of a solid electrolyte oxygen sensor, having an internal electrode and an external electrode, during a dynamically controlled, null balancing, calibration process, the method including: initializing a set of pumping current pulse parameters controlling pulse ON time, post pulse relaxation time and pulse magnitude; applying a pulsed pumping current based on the set of pulse parameters to the internal and external electrodes, wherein the application of current transitions the chamber from a substantially evacuated state to a substantially null or balanced oxygen partial pressure state with respect to an applied external calibration gaseous environment; periodically comparing the Nernst voltage of the sensor to a predetermined limit to determine whether the chamber is at a null or balanced state; comparing an elapsed time from the application of the pulsed pumping current to a third predetermined time limit to determine if the sensor has failed, and progre

Abstract: The present invention relates to a sensor for and a method of detecting carbon monoxide in gas streams containing hydrogen. The sensor acts as a fuel cell and is comprised of a centrally placed membrane electrode assembly upon each side of which is positioned a current collector which has gas inlets that allow gas to flow to the membrane electrode assembly. Plates are positioned on each of the exterior surfaces of the current collectors such that when assembled, one side of the CO sensor forms an anode and the other side forms a cathode. At a constant voltage, a sample gas passes through the sensor such that low levels of Platinum on the sensor facilitate the detection of carbon monoxide. A reader attached to the sensor interprets the concentration of carbon monoxide and air is passed through the sensor for recalibration as needed.

Abstract: A set of methods controls the pumping action of and provides leak checking of a solid electrolyte oxygen sensor having internal and external electrodes. A first method performs a leak check on the sensor by forcing the sensor internal reference chamber to an evacuated state while seeking a minimum pumping current able to maintain this state. Further pumping control methods apply current pulses to the sensor electrodes to achieve a balanced state between an external oxygen partial pressure and an internal reference oxygen partial pressure. Reduction expressions modify the pulse parameters as a function of the sensor voltage output. A further expression modifies the pulse magnitude as a function of the internal reference chamber oxygen partial pressure. A further expression modifies the initial value of the pulse magnitude as a function of the oxygen partial pressure in a calibration gas during a calibration process.

Abstract: This invention provides a gas sensor including a proton-conductive polymer electrolyte layer and a method for measuring gas concentration, that are capable of measuring gas concentration at high accuracy notwithstanding the presence of water vapor.

Abstract: This invention provides an assembly comprising a sensing electrode and a counter electrode in contact with a membrane body formed from a solid polymer electrolyte system comprising a fluorinated polymer matrix and a charge carrying component which is dispersed in the matrix the electrodes and membrane being housed in a housing having a gas diffusion barrier through which gas may flow. The charge carrying components are fluorinated organic proton conductors (such as heptadecafluorooctane sulphonic acid, bis-trifluoromethane sulphonamide, N-(2,6-diethylphenyl)-1,1,1-trifluoromethane sulphonamide, N-benzyltrifluoromethane sulphonamide and N, N-1,2-cyclohexanediylbis (1,1,1-trifluoromethane sulphonamide)). The polymer matrix is a homopolymer or copolymer of vinylidene fluoride preferably with fluorinated comonomers. The solid polymer electrolyte system preferably contains plasticising additive(s) and is cast as a coating onto one or more electrodes eg.

Abstract: This invention provides a pCO2 sensor, and more particularly, a potentiometric pCO2 sensor. The potentiometric pCO2 sensor has a substrate, a solid ion-sensing layer on the substrate, a solid electrolyte layer on the solid ion-sensing layer, and a gas-permeable layer on the solid electrolyte layer. In addition, the gas-permeable layer allows air molecules to diffuse through, the solid electrolyte layer change the pH value thereof according to the CO2 concentration in the diffusing air molecules, and the solid ion-sensing layer senses the pH change of the solid electrolyte layer to generate a sensing signal. By doing so, the quantity of the CO2 dissolved in the liquid can be measured.

Abstract: Disclosed is a gas sensor for controlling a concentration of oxygen and/or measuring NOx by allowing a current to flow through an ion-conductive member for conducting oxygen ion, by the aid of a current supply circuit, wherein the current, which is outputted from the current supply circuit, has a pulse waveform (current signal) having a constant crest value, and the current supply circuit comprises a rectangular wave-generating circuit for controlling a frequency of the current signal on the basis of an electromotive force generated in the ion-conductive member to which the current signal is supplied. Accordingly, it is possible to highly accurately measure the predetermined gas component while scarcely being affected by the electric noise or the like.

Abstract: The invention relates to a method and a device for detecting leaks in the wall of a test object, container or similar, by measuring and evaluating changes that occur in a partial gas pressure. The invention aims to simplify the detection of leaks. To this end, changes that occur in partial pressures of oxygen are detected and evaluated using an oxygen sensor (4).

Abstract: A sensor element and a method for determining the concentration of at least one gas component, especially of a nitrogen oxide, in a gas, mixture. For this purpose, the sensor element includes at least one first electrode exposed to the gas component to be analyzed and at least one reference electrode, which are electrically interconnected by a first solid electrolyte. Furthermore, an electric current between the first electrode and a further electrode is measured continuously or in sampling fashion in response to the application, especially the setting, of an electric voltage between first electrode and the reference electrode due to a chemical reaction proceeding at the first electrode, by which the concentration of the gas component to be analyzed in the gas mixture can be determined. During this process, the application or setting of the electric voltage takes place only during recurring time intervals.

Abstract: A highly accurate, long life, low cost gas sensor is disclosed, particularly useful for measuring carbon monoxide and other toxic gases in an environment. The gas sensor has a first, sensing electrode and a second, counting electrode. Positioned between the first and second electrodes is an ion conducting, solid electrolyte membrane. In response to the presence of a toxic gas introduced to the first electrode, an electric signal is produced between the first electrode and the second electrode. The electric signal changes in response to changes in the concentration of the toxic gas. Detection circuitry measures the electric signal to determine the concentration of the toxic gas. An electrically conductive, hydrophobic top membrane electrically connects the first electrode to the detection circuitry while preventing liquid water from contacting the first electrode. An electrically conductive, hydrophobic bottom membrane electrically connects the second electrode to the detection circuitry.

Abstract: A two-step chemical treatment method for chemically conditioning a sensor element comprising an electrolyte in ionic communication with a first electrode and a second electrode is described. The method comprises treating at least a portion of a sensor element with a first solution comprising an inorganic base, a carbonate salt and an acid salt; heating the sensor element; treating at least a portion of the sensor element with a second solution comprising an inorganic base and a carbonate salt; and drying the sensor element. The gas sensors comprising the two-step treated sensor elements have reduced lean shift, green effect, sensor output amplitude drop, and the light-off time is improved.

Abstract: A CO sensor and a CO-concentration measurement method which enables accurate measurement of CO concentration irrespective of the hydrogen concentration of a gas under measurement. By applying a first predetermined voltage between first and second electrodes 7 and 8, hydrogen contained in a gas under measurement which has been introduced into a first measurement space 2 via a first diffusion-controlling section 1 dissociates, decomposes, or reacts with another element to generate protons. The thus-generated protons are transported from the first electrode 7 to the second electrode 8 via a first proton-conductive layer 5 or protons are transported from the second electrode 8 to the first electrode 7 via the first proton-conductive layer 5 (when the hydrogen concentration of the measurement gas is extremely low), so that the hydrogen concentration within the first measurement space 2 is controlled to a constant level.

Abstract: A gas sensor based on solid electrolyte is proposed for measuring a gas component in a gas mixture, having at least one sensitive region, which has a first means for producing a reaction gas from an additional gas component of the gas mixture. A second means is situated in the sensitive region of the gas sensor, using which the residual content of the reaction gas may be determined, after a reaction that takes place between the reaction gas and the gas component to be measured.

Abstract: Disclosed is a gas sensor for controlling a concentration of oxygen and/or measuring NOx by allowing a current to flow through an ion-conductive member for conducting oxygen ion, by the aid of a current supply circuit, wherein the current, which is outputted from the current supply circuit, has a pulse waveform (current signal) having a constant crest value, and the current supply circuit comprises a rectangular wave-generating circuit for controlling a frequency of the current signal on the basis of an electromotive force generated in the ion-conductive member to which the current signal is supplied. Accordingly, it is possible to highly accurately measure the predetermined gas component while scarcely being affected by the electric noise or the like.

Abstract: Method and sensor for measuring accurate measurement of NOx concentration in an exhaust gas containing O2,H2O, CO2 and NOx and a NOx gas concentration sensor. A first oxygen pump cell sufficiently pumps out oxygen in a measurement gas such as not to decompose NOx. A pair of electrodes is provided on an inner side and an outer side of a second measurement chamber into which the gas is introduced from a first measurement chamber via a diffusion resistance. A voltage is impressed across the paired electrodes for decomposing NOx in the second measurement chamber to dissociate oxygen which causes the current to flow in a second oxygen ion pump cell. The NOx gas concentration is measured for this current. The voltage impressed across the paired electrodes of the second oxygen ion pump cell is set so as not to dissociate H2O and CO2 present in the second measurement chamber.

Abstract: 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.

Abstract: The present invention relates to a sensor for and a method of detecting carbon monoxide in gas streams containing hydrogen. The sensor acts as a fuel cell and is comprised of a centrally placed membrane electrode assembly upon each side of which is positioned a current collector which has gas inlets that allow gas to flow to the membrane electrode assembly. Plates are positioned on each of the exterior surfaces of the current collectors such that when assembled, one side of the CO sensor forms an anode and the other side forms a cathode. At a constant voltage, a sample gas passes through the sensor such that low levels of Platinum on the sensor facilitate the detection of carbon monoxide. A reader attached to the sensor interprets the concentration of carbon monoxide and air is passed through the sensor for recalibration as needed.

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.

Abstract: Disclosed is a gas sensor for controlling a concentration of oxygen and/or measuring NOx by allowing a current to flow through an ion-conductive member for conducting oxygen ion, by the aid of a current supply circuit, wherein the current, which is outputted from the current supply circuit, has a pulse waveform (current signal) having a constant crest value, and the current supply circuit comprises a rectangular wave-generating circuit for controlling a frequency of the current signal on the basis of an electromotive force generated in the ion-conductive member to which the current signal is supplied. Accordingly, it is possible to highly accurately measure the predetermined gas component while scarcely being affected by the electric noise or the like.

Abstract: An electrochemical cell that receives an inlet stream of air and produces an outlet stream of a high oxygen concentration of gas. The cell is made up of a plurality of layers and preferably a porous electrolyte comprised of yttria stabilized zirconia (YSZ) that allows only oxygen ions to pass therethrough and which is covered on its sides with electrodes comprised of lanthanum strontium manganate (LSM) which in turn are coated with a layer of platinum to aid in the even distribution of the electrical current. An electrical current is passed through the electrodes to produce a voltage difference therebetween. The layers of YSZ and LSM are formed by a sol-gel process.

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.

Abstract: A gas sensor is disclosed comprising an oxygen pump cell having at least one exterior pump electrode and at least one interior pump electrode disposed on opposite sides of a first solid electrolyte layer. An emf cell having a first and second emf electrodes and first and second reference gas electrodes are disposed on opposite sides of a second solid electrolyte layer. At least one insulating layer is in contact with the first and second emf electrodes. At least one via hole is disposed through the first solid electrolyte layer. At least one air channel is disposed through at least one insulating layer. An air vent is disposed in at least one insulating layer in contact with the first and second reference gas electrodes. A heater is disposed in thermal communication with the sensor. And at least five electrical leads are in electrical communication with said sensor. A method of using a gas sensor is also disclosed.

Abstract: A method and apparatus which enable accurate measurement of the concentration of NOx in a gas under measurement, even when the NOx concentration is low. A gas under measurement is introduced into a first chamber 3 through a first diffusion passage 2. A pump voltage V1 is applied from a direct-current power source E1 to a first oxygen ion pump cell 6 such that the electric potential of an oxygen-concentration-measuring cell 7 is held constant. As a result, oxygen is pumped out from the first chamber 3 such that the oxygen concentration measured at an inlet to a second chamber 5 becomes constant. A first pump current Ip1 flowing to the first oxygen ion pump cell 6 is measured. Next, the gas under measurement contained in the first chamber 3 is introduced into the second chamber 5 through a second diffusion passage 4.

Abstract: An electrochemical gas sensor and a method for determining the concentration of gaseous components in a gas mixture, particularly of NOx in exhaust gases of internal combustion engines. The gas sensor includes a first measuring-gas compartment which is in communication with the measuring gas, and two additional measuring-gas compartments which are connected to the first measuring-gas compartment via diffusion barriers. The first measuring-gas compartment contains a first pump cell which, with the aid of pump electrodes arranged on a solid electrolyte, transports oxygen into and out of the measuring-gas compartment. The second and third measuring-gas compartments contain further pump cells, the second measuring-gas compartment being used for measuring the oxygen concentration of the mixture, and the third measuring-gas compartment being used for measuring the sum of the oxygen concentration and the concentration of the gaseous component in the gas mixture.

Abstract: A CO gas sensor is equipped with a detecting unit in which a solid electrolyte membrane is held between a detection electrode and a counter electrode, and a voltage applying unit which applies voltage between the detection electrode and the counter electrode and changes the voltage. The detection electrode includes an electrochemically active first catalyst in an electrically conductive porous body, a reaction layer having a density of 1 ng/cm2-100 &mgr;g/cm2 and having a thickness of 0.3 nm-15 &mgr;m, and the counter electrode includes an electrochemically active second catalyst carried on an electrically conductive porous body.

Abstract: A conductive co-fired body for an electrochemical cell for an exhaust sensor comprises zirconia, yttrium oxide, and alumina. The body comprises about 15 to about 30 weight % monoclinic phase zirconia. This produces an electrochemical cell having low impedance wherein the zirconia body and alumina body are co-fired. One method for manufacturing the electrochemical cell comprises combining zirconia, yttria, and alumina with solvent and dispersant to form a mixture. After, binder is added to the mixture which is then de-aired and cast onto a tape surface. The tape is dried, metallized, and laminated to an unfired alumina surface. The structure is then co-fired to form a body for said electrochemical cell.

Abstract: The protective shield arrangement for an exhaust sensor and method of making and using the same is achieved by providing a protective shield for an exhaust gas sensor that comprises a porous mesh material formed as a cap for placement over an end portion of a sensing element. This is formed by a method that comprises providing a unitary piece of the mesh material, and folding the mesh material to form the cap. Thereby, gas passes through the tortuous pathway created by the mesh material to be sensed by the sensor.

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.

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.

Abstract: An electrochemical sensor for ascertaining a gas concentration of a measuring gas includes an electrochemical element, including a first solid electrolyte body having an electrochemical pump cell and a first and a second electrode, and having a gas compartment which is connected via a gas access opening to the measuring-gas compartment, and in which one of the two electrodes is arranged. The electrochemical element further includes a second solid electrolyte body having an electrochemical sensor cell (Nernst cell) and a third and a fourth electrode. The surface of the first solid electrolyte body faces the measuring-gas compartment, and the gas access opening is covered by a porous protective layer. The electrochemical sensor includes a layer that exhibits a higher density or a lower porosity compared to the protective layer and that is allocated to the porous protective layer.

Abstract: The electrolyte comprises up to about 80 wt % zirconia, up to about 30 wt % stabilizer, and up to about 40 wt % dopant-zirconia. Alternatively, the electrolyte can comprise zirconia having a phase chemistry, wherein the phase chemistry, at about 25° C.

Abstract: A gas sensor is disclosed comprising an oxygen pump cell having at least one exterior pump electrode and at least one interior pump electrode disposed on opposite sides of a first solid electrolyte layer. An emf cell having a first and second emf electrodes and first and second reference gas electrodes are disposed on opposite sides of a second solid electrolyte layer. At least one insulating layer is in contact with the first and second emf electrodes. At least one via hole is disposed through the first solid electrolyte layer. At least one air channel is disposed through at least one insulating layer. An air vent is disposed in at least one insulating layer in contact with the first and second reference gas electrodes. A heater is disposed in thermal communication with the sensor. And at least five electrical leads are in electrical communication with said sensor. A method of using a gas sensor is also disclosed.

Abstract: An oxygen concentration detector comprises a solid electrolyte 21, a sensing element 2 which consists of the solid electrolyte 21 coated on the surface with an outer electrode 23, a heater 3 provided inside the solid electrolyte 21, and a protecting cover 16 which protects the sensing element 2. The protecting cover 16 has two levels of openings 161, 162, the outer electrode 23 is constructed within the range defined by the length of the heat-generating part 31 of the heater 3, and the relationship between the length L1 of the heat-generating part 31 and the distance between the openings L2 of the two levels of openings 161, 162 in the axial direction is such that L1/L2=0.9 to 1.3.

Abstract: An exhaust gas sensor element having an electrochemical cell, a protective material in fluid communication with the electrochemical cell, and a reactive inhibitive coating disposed over the protective material. The reactive inhibitive coating prevents the reaction of compounds with acids(e.g., phosphates) in the exhaust gas, which may form a dense glass layer on the outside of the gas sensor. The reactive inhibitive coating is either an alkaline earth oxide ethoxide, and/or carbonate that is deposited on the gas sensor to a thickness so as to preferably provide an excess of either the alkaline earth material.

Abstract: A method of making a gas sensor is disclosed, comprising disposing an electrochemical cell comprising a sensing electrode and a reference electrode disposed in ionic communication with and on opposite sides of an electrolyte layer. A first insulating layer is disposed in contact with the sensing electrode. A second insulating layer is disposed in contact with the reference electrode. A first protective insulating layer and a first heater are disposed in contact and in thermal communication with the first insulating layer. A second protective insulating layer and a second heater are disposed in contact with and in thermal communication with the second insulating layer. The method includes forming a sensor and co-firing the sensor. A gas sensor is also disclosed as being made according to the above-referenced method.

Abstract: To determine the oxidizable portion of exhaust gases in the presence of the reducible portion with the legally required precision, a method and a sensor are disclosed for analyzing a flow of exhaust gas components. The sensor includes a limit current measurer, one limit current pump for reducible gases and, downstream from this pump in the direction of diffusion, another limit pump for oxidizable gases. The electrodes of the limit current pump for reducible gases are made of a material that does not catalyze the reaction between oxidizable and reducible gases.

Abstract: A gas sensor comprising an electrolytic cell having detecting and reference electrodes connected by a solid electrolyte. In a first embodiment, both electrodes comprise Ag2CO3 and Ag4RbI5, and the electrolyte is Ag4RbI5, the reference electrode being in contact with a reference gas. In a second embodiment, the reference electrode is a silver electrode and no reference gas is needed. The sensor is operable at room temperature to measure CO2 concentrations, and is relatively unaffected by water vapor.

Abstract: An oxide ion conductor is manufactured having a relatively high mechanical strength while the ionic conduction thereof is maintained at a satisfactory level. The oxide ion conductor is represented by the formula Ln11-xAxGa1-y-z-wB1yB2zB3wO3-d. In the oxide ion conductor, Ln1 is at least one element selected from the group consisting of La, Ce, Pr, Nd, and Sm, A is at least one element selected from the group consisting of Sr, Ca, and Ba, B1 is at least one element selected from the group consisting of Mg, Al, and In, B2 is at least one element selected from the group consisting of Co, Fe, Ni, and Cu, and B3 is at least one element selected from the group consisting of Al, Mg, Co, Ni, Fe, Cu, Zn, Mn, and Zr, wherein x is 0.05 to 0.3, y is 0.025 to 0.29, z is 0.01 to 0.15, w is 0.01 to 0.15, y+z+w is 0.035 to 0.3, and d is 0.04 to 0.3.

Abstract: A method of stabilizing pump current in a gas sensor through suppression of oscillations of the pump current which result from pulsations of measured gas is provided. The gas sensor includes an oxygen pump element, an oxygen concentration cell element and a measurement gap between the oxygen pump element and the oxygen concentration cell element, and is operative to control the pump current through the oxygen pump element so that an output voltage of the oxygen concentration cell element is constant in order that an oxygen concentration in the measurement gap is maintained constant and detect an oxygen concentration in the measured gas on the basis of the pump current. The method comprising adjusting an activity of electrodes of an oxygen pump element so as to change a responsiveness in control of the pump current and thereby reduce an amplitude of the oscillations of the pump current.

Abstract: According to the present invention, there is provided: a sensor element including an oxygen concentration detection section consisting of solid electrolyte for outputting a detection signal corresponding to an oxygen concentration in a hollow chamber to which an exhaust of an internal combustion engine is introduced and an oxygen pump section for controlling an electric current to be applied to a solid electrolyte wall that divides the hollow chamber from an exhaust side of the engine so that the oxygen concentration in the hollow chamber becomes a predetermined oxygen concentration, to flow oxygen into/out of the hollow chamber; an air-fuel ratio detection circuit for outputting an air-fuel ratio detection value based on the electric current applied to the solid electrolyte wall by the oxygen pump section; and a pump current cut off circuit for cutting off the power supply to the solid electrolyte wall by the oxygen pump section, and a detection value of air-fuel ratio is corrected based on an output value o

Abstract: Each gas sensing element, with a measured gas sensing electrode and a reference gas sensing electrode provided on opposite surfaces of a solid electrolytic body, is manufactured to have a limit current value whose initial value is offset from a target value. Electric power is supplied to each manufactured gas sensing element to adjust the limit current value from the initial value to the target value.

Abstract: A method is provided for determining the oxygen content of a measurement gas using a sensor, as well as the use of the sensor according to the method. The problem presents itself of making available a method by which lambda can be determined as accurately and as simply as possible in a broad range of 0.8 to about 20. The problem is solved for the method in that the determination of the oxygen content of the measurement gas is performed by the first and the second measuring cells in a serial manner, wherein the oxygen content of the measurement gas is determined by the second measuring cell in a lambda range of 0.8 to 1.4 and by the first measuring cell in a lambda range of ≧1 to 20.

Abstract: The present invention is an electrolyte composition in bulk, thick film and sputtered thin film form forming with different metal sensing and reference electrodes a highly stable gas component concentration sensor.

Abstract: The present invention provides a solid electrolyte having high stability against humidity at room temperature and a carbon dioxide sensor which not only can have sufficient sensitivity but also has excellent responsiveness at room temperature and which is excellent in humidity resistance due to the use of the above solid electrolyte, the solid electrolyte of the present invention being formed by heat-treating a polymer having a quaternary ammonium group in its main chain and having a halide ion as counter ion, and a metal halide, the carbon dioxide sensor of the present invention comprising a detection electrode and a reference electrode formed respectively in contact with a solid electrolyte, the detection electrode containing a metal carbonate which forms a dissociation equilibrium with carbon dioxide, the solid electrolyte being a product formed by heat-treating a compound having an ammonium ion portion and a metal halide or a product formed by heat-treating a polymer having a quaternary ammonium group in

Abstract: A galvanic solid electrolyte sensor for measuring gaseous anhydrides includes a ceramic solid electrolyte that has a material that conducts electrons, a measuring electrode that includes a pure or doped alkaline or alkaline earth salt and a reference electrode spatially separated from the measuring electrode and sealed off from the anhydride measuring gas by a gas-tight enclosure. The reference electrode is made of a metal material that conducts electrons. The gas-tight enclosure is made of a layer of a glass containing zirconium and lead that covers only the material of the reference electrode, with only a marginal area of this layer abutting the solid electrolyte.

Abstract: The invention is directed to a method for detecting the oxygen content in a gas to be measured. At least one concentration cell operating in accordance with the Nernst principle is provided. The concentration cell includes a measuring electrode communicating with the gas and a solid electrolyte and a reference electrode connected to the measuring electrode through the solid electrolyte. A pump-current pulse is applied between the reference electrode and the measuring electrode and, directly after the end of each pump-current pulse, the current flow between the reference electrode and the measuring electrode is reversed in a pulse-like manner.

Abstract: The invention relates to a galvanic cell comprising a) an oxygen-ion-conducting solid electrolyte, b) a gas-sensitive material which contains at least one salt having the structural formula Mem(XOn)p, where Me is a metal, X stands for C, S or N, and the symbols m, n and p characterize the respective stoichiometric relations, c) a material, interposed between the oxygen-ion-conducting solid electrolyte and the gas-sensitive material, which allows conduction both by cations of the metal Me and by electrons and which seals off a potential-determining area of the solid electrolyte surface from the surroundings, making it impervious to gases therein, and d) two electronically conductive potential taps at surface areas of the oxygen-ion-conducting solid electrolyte.