Abstract: Disclosed herein is a gas sensor cell comprising a solid electrolyte layer comprising a first solid electrolyte layer surface, a sensor electrode disposed on the first solid electrolyte layer surface, a reference electrode disposed on the first solid electrolyte layer surface, and an insulating layer comprising a first insulating layer surface and a second insulating layer surface opposite the first insulating layer surface, wherein the first insulating layer surface is disposed on the first solid electrolyte layer surface, and wherein the sensor electrode is in fluid communication with a gas. Also disclosed is a method of adjusting an impedance of the gas sensor cell, comprising adjusting a structural dimension of a sensing end of the gas sensor cell, wherein the sensing end comprises the sensor electrode and the reference electrode.

Abstract: A method of treating a gas sensor element for improving measurement characteristics thereof, including: heating the gas sensor element at a temperature of 600-1000° C. for 3-24 hours in a treatment atmosphere in which an oxygen concentration is regulated to be not higher than 0.2% and in which are included: (A) not lower than 1000 ppm of an adsorptive gas component wherein an adsorptive capable of being adsorbed on the measuring electrode is bound to oxygen; and (B) a combustible gas in an amount that can be substantially stoichiometrically oxidized by oxygen that is generated upon reduction or decomposition of the adsorptive gas component, so that the adsorptive gas component is reduced or decomposed for permitting the adsorptive in the adsorptive gas component to be adsorbed on the measuring electrode, and so that the noble metal material of the measuring electrode is reduced.

Abstract: Sulfur resistant sensors and a process analytic system employing such sensors are provided. The sensors generally include a treatment or material that is adapted to increase the resistance of certain portions of the sensors to exposure to sulfur. In one aspect, an improved sulfur-resistant process analytic system includes a probe with one or more sulfur-resistant sensors therein coupled to a controller, a thermal control module, and a source of blowback gas.

Abstract: The invention relates to a gas sensor for determining the oxygen concentration in a gas mixture, especially in the exhaust gas of internal combustion engines. Said gas sensor comprises a pump cell having an outer pump electrode, exposed to the gas mixture, and an inner pump electrode, exposed to the gas mixture via a diffusion barrier, and a solid electrolyte body interposed between the outer pump electrode and the inner pump electrode. The gas sensor also has a reference electrode, exposed to a reference gas, and a sensor heating device. The outer pump electrode is connected to a circuit arrangement via a pump current line, the inner pump electrode via a measuring line, the reference electrode via a reference current line and the sensor heating device via two heating lines.

Abstract: The present invention generally relates to carbon dioxide (CO2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO2) sensor that incorporates lithium phosphate (Li3PO4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li2CO3) and barium carbonate (BaCO3). In another embodiment, the present invention relates to a carbon dioxide (CO2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO2) sensors having lithium phosphate (Li3PO4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li2CO3) and barium carbonate (BaCO3).

Abstract: A gas sensor element which may be employed in measuring the concentration of gas such O2 is provided. The gas sensor element is of a laminated type and designed to introduce gas to be measured into a measurement gas chamber through a diffusion resistor. The measurement gas chamber has a volume of 0.15 mm3 in order to facilitate expelling of the gas remaining within the measurement gas chamber during transition of thermal activation of the gas sensor element.

Abstract: A sensor element for determining the concentration of gas components in gas mixtures, e.g., for determining the oxygen concentration in exhaust gases of combustion engines, includes: at least one electrochemical measurement cell that encompasses a first and a second electrode in contact with a solid electrolyte material; a heating element for heating the sensor element to operating temperature; and a cavity integrated into the sensor element. The cavity exhibits, in at least one region close to the lateral delimiting surfaces of the cavity, a diameter that is greater than zero and smaller than the diameter in its central region.

Abstract: The present invention provides a gas sensor which allows separation to hardly occur. A gas sensor 1 includes a gas detecting section 2 and a heater section 8 secured in the gas sensor, the heater section 8 including a heating element 3 and a support 9 which supports at least the heating element 3. An opening section 4 is provided to reduce pressure generated between the heating element 3 and the support 9.

Abstract: A gas sensor is disclosed including a gas-concentration detecting element, a casing accommodating the gas-concentration detecting element, a lead wire delivering a detected voltage potential to an outside, an insulator holding the lead wire in electrical relationship with respect to the housing, a columnar elastic sealing member, air holes formed in the casing for admitting atmospheric air to an inside thereof, and a water repellent filter. The water repellent filter, formed in a cylindrical shape, is disposed between the casing and the insulator, and a cylindrical elastic member is disposed in at least one of an area between the water repellent filter and the casing and another area between the water repellent filter and the insulator. With the casing caulked, the water repellent filter and the cylindrical elastic member are fixed in place.

Abstract: An ammonia gas sensor which includes a solid electrolyte member (310) extending in an axial direction; a reference electrode (320) provided on the solid electrolyte member (310); and a detection electrode (331) and a selective reaction layer (340) provided on the solid electrolyte member (310). The detection electrode serves as a counterpart of the reference electrode (320). The detection electrode (331) contains a noble metal as a predominant component, and the selective reaction layer (340) contains a metal oxide as a predominant component.

Abstract: A concentration detector comprises oxygen-forming means for forming oxygen by decomposing the particular component in the gas, first output means for producing an output value proportional to the oxygen concentration in the gas of before oxygen is formed by the oxygen-forming means, second output means for producing an output value proportional to the oxygen concentration in the gas after oxygen is formed by the oxygen-forming means, concentration calculation means for calculating the concentration of the particular component in the gas based upon the output value from the first output means and upon the output value from the second output means by using a coefficient for bringing the output characteristics of the first output means into agreement with the output characteristics of the second output means, and means which feeds at least two kinds of gases containing the particular component at a constant concentration and containing oxygen at different concentrations to said first output means and calculates

Abstract: A gas sensor is provided for determining the concentration of a gas component in a measuring gas, in particular for determining the oxygen concentration in the exhaust gas of internal combustion engines, which has an electrode pair situated on a solid-state electrolyte and made up of an outer pump electrode and an inner pump electrode, which is accessible to the measuring gas supplied via a diffusion barrier, the electrode pairs being triggered in a clocked manner and having a potential of varying polarity applied in each clock-pulse period. To improve the measuring precision of the gas sensor without additional electrodes, a cavity is situated between the diffusion barrier and the inner pump electrode, the cavity serving as storage volume for the oxygen pumped through the solid-state electrolyte.

Abstract: A gas sensor element including: a solid electrolyte layer having a first surface and a second surface; a first electrode formed on the first surface of the solid electrolyte layer; a second electrode formed on the second surface of the solid electrolyte layer; and an insulating layer provided between the first electrode and the first surface of the solid electrolyte layer. The insulating layer covers an outer edge of the first electrode and has an opening through which a portion of the first electrode is exposed. The opening has an area that is smaller than that of the second electrode, and is provided at a position opposite the second electrode to form a detection portion constituted by the portion of the first electrode exposed through the opening, the second electrode and the solid electrolyte layer.

Abstract: A gas sensor element is equipped with a hollow body which is closed at one of opposed ends and has a gas inlet formed in the other end through which gas to be measured enters. The hollow body includes an oxygen ion-conductive solid electrolyte member, a gas-exposed electrode which is affixed to a first area of an inner surface of the solid electrolyte member, and a reference gas-exposed electrode which is affixed to a second area of an outer surface of the solid electrolyte member. The second area is aligned with the first area in a direction perpendicular to a flow of the gas. A heater is disposed on an area of the hollow body which faces the electrodes. This structure servers to minimize direct exposure of water carried by the flow of the gas to a heated area of the hollow body, thereby avoiding cracks in the hollow body.

Abstract: This device is a degradation judging device for an oxygen sensor having a reference electrode 23 and a measuring electrode 22, both of which hold a solid electrolyte layer therebetween, and measuring oxygen concentrations based on an electromotive force that occurs in accordance with a difference between an oxygen partial pressure of the reference electrode 23 and an oxygen partial pressure of the measuring electrode 22. A control unit 10, which controls operations of intake and exhaust valves, a spark plug and a fuel injection valve, has a degradation judging means that detects an internal resistance value “R1” of the solid electrolyte layer 21 by applying a high-frequency alternating current between the reference electrode 23 and the measuring electrode 22, and judges degradation of the solid electrolyte layer 21 by comparing an average value of the detected internal resistance value “R1” with a reference value.

Abstract: A gas sensor and a related manufacturing method are disclosed. The gas sensor includes a detecting unit including a concentration detecting element, composed of a solid electrolyte body having inner and outer walls formed with electrodes, a housing, and output terminals, and an output extracting unit including at least signal wires, power conducting wires, output extracting terminals, power conducting terminals, an insulator and a casing. The detecting unit and the output extracting unit are coupled to each other in the insulator such that the output terminals and the output extracting terminals are conducted to each other within the insulator.

Abstract: A gas sensor and a related manufacturing method are disclosed. The gas sensor includes a detecting unit comprised of a concentration detecting element, composed of a solid electrolyte body having inner and outer walls formed with electrodes, a housing, output terminals and a heater, and an output extracting unit comprised of at least signal wires, power conducting wires, output extracting terminals, power conducting terminals, an insulator and a casing. The detecting unit and the output extracting unit are united to each other in the insulator such that the output terminals, holding a base body of the heater in electrical insulation, and the output extracting terminals are conducted to each other and the heater electrodes and the power conducting terminals are conducted to each other upon which a boss portion of the housing is fixedly fitted to a leading end portion of the casing.

Abstract: A gas sensing element has at least a sensor cell consisting of a measured gas side electrode positioned in a measured gas chamber, a reference electrode being operative association with the measured gas side electrode, and a solid electrolytic substrate having surfaces on which the measured gas side electrode and the reference electrode are formed. The measured gas side electrode of the sensor cell contains at least one additive selected from the group consisting of Au, Ag, Cu, and Pb by an amount of 0.01 wt % to 2.0 wt % (external wt %) when an overall amount of the measured gas side electrode is 100 wt %.

Abstract: An improved structure of a gas sensor is provided which is designed to minimize thermal damage to a water-repellent filter installed in a base end portion of the gas sensor. The gas sensor has an elastic seal installed in an opening of the base end portion of the gas sensor and an air cover assembly made up of a main cover and a filter cover. The filter cover is crimped to form at least two necks which establish joints of the filter cover to the main cover through the water-repellent filter. At least one of the necks is used to retain the elastic seal within the main cover. This structure locates the water-repellent filter farther away from the top of the gas sensor exposed to intense heat, thereby minimizing the thermal deformation or deterioration of the water-repellent filter.

Abstract: Provided is a multilayer gas sensing element having a high measurement accuracy and less susceptible to a leakage current. The element comprises an oxygen pump cell for adjusting an oxygen concentration in a measured gas chamber, a sensor cell for detecting a specified gas concentration in the measured gas chamber, and a heater for heating the cells up to an activating temperature. The heater includes a heat generator for generating heat when energized, a heater terminal provided externally and a heater lead for making electrical connection therebetween. When the electrical resistance value of the heat generator is taken as RH and the electrical resistance value of the heater lead is taken as RL, these values are set to satisfy the relationship of 1.5?RH/RL.

Abstract: A quickly activatable structure of a gas sensor element includes a measurement gas electrode, a reference gas electrode, a solid electrolyte layer to which the measurement and reference gas electrodes are affixed, and a heater. The heater has a heating element to heat the solid electrolyte layer. A reference gas chamber is defined between the solid electrolyte member and the heater and has a length made up of a first chamber and a second chamber. The first chamber is located in a heating area in which the heating element is disposed. The second chamber is located in a non-heating area and has at least a portion which is greater in volume per unit length of the reference gas chamber than the first chamber, thereby decreasing the dissipation of thermal energy to the non-heating area, which enhances the thermal transfer from the heating element to the solid electrolyte member.

Abstract: An inner terminal installation jig used to install an inner electrode terminal mount formed on an inner peripheral surface of a hollow cylindrical sensor element of a gas sensor.

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: 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: The reference air channel of a gas sensor or a lambda probe having a laminate body produced by printing technology is provided. The laminate body is produced by printing a suitably structured layer onto a neighboring layer, for example, by screen printing.

Abstract: A gas sensor element which may be employed in measuring the concentration of gas such O2, NOx, or CO. The gas sensor element consists of an electrochemical cell made up of a solid electrolyte body formed by a partially stabilized zirconia and a pair of electrodes disposed on the solid electrolyte body. The electrochemical cell is subjected to an aging treatment in which the dc current is applied to the electrodes at a given voltage to enhance the activation of the electrochemical cell.

Abstract: A method for purifying the exhaust gas from an internal combustion engine, which is operated under lambda-based closed loop control and which has an exhaust gas tract in which is located a catalytic converter, is provided. According to this method, a pre-converter lambda value for the exhaust gas is continuously sensed upstream of the catalytic converter, from which a pre-converter lambda signal is generated, and this pre-converter lambda signal is used as the reference variable for the lambda control loop. A post-converter lambda value for the exhaust gas is continuously sensed downstream from the converter, from which a post-converter lambda signal is generated, this being a monotonically decreasing function of the lambda value for the exhaust gas downstream from the catalytic converter.

Abstract: An electrochemical sensor, in particular for determining the oxygen content in exhaust gases of internal combustion engines, has a solid electrolyte element having at least one first electrode, at least one second electrode, and at least one heating element. The second electrode located to the heating element is connected to ground, and the first electrode coacting with the second electrode is negatively polarized, a negative operating voltage being provided.

Abstract: A gas sensor includes a measurement gas chamber into which a measurement gas is introduced. An oxygen pumping cell adjusts an oxygen concentration in the measurement gas chamber. An oxygen monitor cell has a monitor electrode exposed in the measurement gas chamber. The monitor electrode has an oxidizing activity with respect to a specific component of the measurement gas. A sensor cell has a sensor electrode exposed in the measurement gas chamber. The sensor electrode has an oxidizing activity with respect to the specific component of the measurement gas which is lower than the oxidizing activity of the monitor electrode. An oxygen-ion current in the oxygen monitor cell is detected. An oxygen-ion current in the sensor cell is detected. A concentration of the specific component of the measurement gas is detected from a relation between the detected oxygen-ion currents in the oxygen monitor cell and the sensor cell.

Abstract: A method for operating an internal combustion engine includes the step of measuring emission values of at least two pollutant components of an exhaust gas of an internal combustion engine. A value of at least one operating parameter of the internal combustion engine is changed in order to decrease an emission value of a first pollutant component if the emission value of the first pollutant component exceeds a given maximum threshold value. An emission value of a second pollutant component is monitored in order to determine whether the emission value of the second pollutant component remains below a maximum value for the second pollutant component and whether an increase in the emission value to the maximum value for the second pollutant component is permitted.

Abstract: A solid electrolyte-based sensor element of a gas sensor for determining a gas component in a gas mixture is described, in particular for determining the concentration of oxygen and/or nitrogen oxides in exhaust gases of internal combustion engines. The sensor element has an electrochemical cell that includes a first and a second electrode, both electrodes being located in internal gas spaces of the sensor element. The internal gas space in which the first electrode is located is largely in the same layer plane of the sensor element as at least one other internal gas space of the sensor element in which the second electrode or a reference electrode are located.

Abstract: A planar sensor element for determining gas components, which includes a layer structure with a heating element integrated therein with a layer-shaped heating conductor. The heating conductor is arranged in a layer plane of the layer structure so that an at least approximately homogeneous distribution of the heating power of the heating element over the cross-section of the layer structure is obtained.

Abstract: A coating system and a method for its manufacture are provided. An electrically conductive base coat and a porous overcoat lying over the base coat are arranged on a ceramic substrate. At least one additional deposited layer is arranged on the base coat in such a way that the additional layer is formed in the pores of the porous overcoat adjacent to the base coat. The additional layer is deposited either by currentless or electrolytic deposition. For electrolytic deposition of the additional layer, the ceramic substrate sintered with the base coat and the overcoat is submerged in an electrolytic bath and the base coat is connected as a cathode. The currentless deposition takes place from a solution of the metal to be deposited with the addition of a reducing agent.

Abstract: A gas sensing element includes a solid electrolytic substrate having oxygen ion conductivity, a measured gas side electrode provided on a surface of the solid electrolytic substrate so as to be exposed to a measured gas, and a reference gas side electrode provided on another surface of the solid electrolytic substrate so as to be exposed to a reference gas. The measured gas side electrode is covered by a porous electrode protecting layer. A limit current density of the electrode protecting layer is in a range from 0.04 mA/mm2 to 0.15 mA/mm2 on a unit area of the reference gas side electrode.

Abstract: A gas sensor for determining a physical quantity of a gas component, e.g., in an exhaust gas of an internal combustion engine, including a sensor element which contains at least one electrochemical cell. The electrochemical cell includes a first electrode and a second electrode that are arranged at a distance on at least one solid electrolyte, the second electrode is arranged in a reference gas space. A third electrode which is in contact with a gas located in the gas space is provided. The gas component may be exchanged between the gas space and the reference gas space using a voltage applied between the second electrode and the third electrode.

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).

Abstract: A gas concentration measuring apparatus has a gas sensor consisting of pump, sensor, and monitor cells. The apparatus works to determine the value of voltage applied to the pump cell when a change in current produced by the monitor cell or the sensor cell changes upon a change in the voltage applied to the pump cell varies greatly and uses it to determine a control point to which the voltage applied to the pump cell is to be controlled. This keeps a gas concentration measuring accuracy free from, for example, aging of the sensor.

Abstract: A gas concentration measuring apparatus has a gas sensor including pump, sensor, and monitor cells. The apparatus works to look up a predetermined voltage-to-current relation to determine an initial value to be applied to the pump cell as a function of a current output of the pump cell, apply the initial value of the voltage to the pump cell, and to sweep it temporarily. The apparatus works to correct the initial value of the voltage as a function of a current output of the sensor cell upon the sweep of the initial value of the voltage applied to the pump cell, thereby better maintaining gas concentration measuring accuracy with respect to, for example, aging of the sensor.

Abstract: A heating device for a gas sensor, in particular for use in the exhaust gas analysis of internal combustion engines, including a heating element having an electrical resistor layer. The heating element is embedded in a first insulation which in turn is surrounded, at least in part, by a second insulation. The first and the second insulation have different porosities.

Abstract: A manufacturing method for a gas senor having sensor element on and in which an outer electrode terminal and an inner electrode terminal are press-fitted. The manufacturing method features stability of installation of the outer and inner electrode terminals without causing physical damage to the sensor element. Outer and inner terminal installation jigs are used in the method.

Abstract: A probe is described for determining an oxygen concentration in a gas mixture, in particular in the exhaust gas of internal combustion engines, having a Nernst measuring cell, which has a first electrode (Nernst electrode) which is exposed to the gas mixture to be measured via a diffusion barrier, a second electrode (reference electrode) which is exposed to a reference gas, and a solid electrolyte body arranged between the first and the second electrode, and having a pump cell, which has a first electrode (inner pump electrode) which is exposed to the gas mixture via the diffusion barrier, a second electrode (outer pump electrode) which is exposed to the gas mixture, and a solid electrolyte body arranged between the first and the second electrode. The Nernst electrode and the inner pump electrode are connected at least in some sections via a joint supply conductor to a circuit arrangement for controlling and evaluating the probe.

Abstract: A sensor element for determining the concentration of a gas component in a gas mixture, particularly for determining the oxygen concentration in exhaust gases of internal combustion engines. The sensor element includes at least one pump cell, which has at least one first pump electrode located in a measuring gas chamber and at least one second pump electrode, located on a surface of the sensor element facing the gas mixture, as well as at least one concentration cell, which has at least one reference electrode located in a reference gas chamber and at least one measuring electrode, located in the measuring gas chamber, which cooperates with the reference electrode. The measuring gas chamber and the reference gas chamber are essentially located in the same layer level (plane) of the sensor element which has a layered construction.

Abstract: In order to raise accuracy of measurement, a compound layered type of sensing device is provided. The device comprises a plurality of solid electrolyte plates and first to third electrochemical cells. Each cell has a single pair of electrodes disposed on the solid electrolyte plates. A concentration of a gas specified from a gas to be measured pre-processed based on oxygen pumping by the first electrochemical cell is detected by the second electrochemical cell. A difference in electromotive force between the gas to be measured and a reference gas is detected by the third electrochemical cell. The single pair of electrodes of the third electrochemical cell is disposed on the same surface of one of the solid electrolyte plates, and both of the first and third electrochemical cells are located with different ones of the solid electrolyte plates.

Abstract: A gas sensor includes a first space for a measurement gas from a gas-introducing hole via a first diffusion rate-determining section, a main pumping means for controlling a partial pressure of oxygen in the measurement gas introduced into the first space to have a predetermined value, a second space for the measurement gas from the first space via a second diffusion rate-determining section, and a measuring pumping means for reducing or decomposing a NOx component in the measurement gas introduced from the second space via a third diffusion rate-determining section so that oxygen produced thereby is pumped out to detect a current generated by pumping out the oxygen. A ratio (Wc/We) between a width (We) of an end of a sensor element and a width (Wc) of the gas-introducing hole is not less than 30% and less than 70%.

Abstract: A gas sensor comprises a first electrode and a reference electrode with an electrolyte disposed therebetween, wherein the first electrode and said reference electrode are in ionic conmmunication, wherein the reference electrode has a surface on a side of the reference electrode opposite the electrolyte and the surface has a surface area. The gas sensor also comprises a reference gas channel in fluid communication with the reference electrode, wherein at least a portion of the surface of the reference electrode physically contacts at least a portion of the reference gas channel, and wherein the portion of the reference electrode in physical contact with the reference gas channel is less than about 90% of the surface area.

Abstract: A gas-detecting element comprising an oxygen-ion-conductive solid electrolyte substrate, a sensing electrode fixed onto said solid electrolyte substrate and active with a detection object gas and oxygen, and a reference electrode fixed onto said solid electrolyte substrate and active with at least oxygen, for detecting potential difference between the sensing electrode and the reference electrode to determine the concentration of the detection object gas, the sensing electrode and/or the reference electrode being covered by an electrode-coating layer made of an oxygen-ion-conductive solid electrolyte, and the electrode-coating layer having a portion bonded to the solid electrolyte substrate directly or via an electrode underlayer made of an oxygen-ion-conductive solid electrolyte.

Abstract: The present invention discloses a NOx sensor for accurately detecting the total concentration of nitrogen oxides in a measured gas without being affected by interference gases. The sensor comprises a gas treatment chamber 5 arranged at the prior stage of the gas detection chamber 3, an inorganic porous member 25 loaded in the gas treatment chamber, and a NOx conversion pumping cell 14, 15 and/or an oxygen supplying pumping cell which supplies oxygen into the gas treatment chamber. When the measured gas is introduced in the gas treatment chamber, the interference gases contained in the measured gas are effectively oxidized by the supplied oxygen under the assistance of the catalytic activity of inorganic porous member. The total amount of the nitrogen oxides is measured in the gas detection chamber while NOx in the measured gas are converted into a single component (NO2 or NO) by the NOx conversion pumping cell after the interference gases are oxidized.

Abstract: A gas sensor for measuring an amount of a measurement gas component, including a solid electrolyte having an internal space, a gas-introducing port for introducing measurement gas from an external space into the internal space, diffusion rate-determining means between the internal space and the gas-introducing port, and inner and outer pumping electrodes for pumping-processing oxygen contained in the measurement gas. The diffusion rate-determining means includes slits each having, when viewed in a plane substantially perpendicular to a longitudinal extension axis thereof, two dimensions, with at least one dimension of each slit being not more than 10 microns.

Abstract: A sensor element for determining the concentration of gas components in gas mixtures, particularly for determining the oxygen concentration in exhaust gases of internal combustion engines. It contains a pump cell, which pumps oxygen into or out of a measuring gas chamber, as well as a concentration cell, which has a reference electrode situated in the reference gas channel, and has a measuring electrode. The measuring gas chamber and the reference gas channel are situated in the same layer plane of the sensor element, and are separated from each other by a partition, which is produced by applying a ceramic paste to an adjacent, solid electrolyte foil.

Abstract: An improved method for dehydration and concentration of an aqueous solution containing an organic compound is disclosed. The solution is evaporated to produce a gaseous mixture comprising an organic compound vapor and a water vapor. The water vapor is selectively removed from the gaseous mixture by permeation through an aromatic polyimide gas separation membrane while the gaseous mixture being kept in contact with a surface on one side of the gas separation membrane at a temperature of 70.degree. C. or higher to obtain a gaseous mixture comprising the organic compound vapor and a reduced amount of a water vapor.