Abstract: A gas sensor including a plate-shaped laminate disposed in a housing and fixed thereto via an element passage member and formed by laminating a gas sensor element and a heating element. The gas sensor element includes a plate-shaped solid electrolyte member, and a pair of detection electrodes formed on front and back surfaces thereof and constituting, in cooperation with the solid electrolyte member, a detection section for detecting the concentration of a specific gas. Insulating substrates mainly composed of alumina are provided on opposite sides of the laminate in the laminating direction. Coating layers mainly composed of a first material higher in toughness than alumina are formed on at least portions of outer surfaces of the insulating substrates in the laminating direction, the portions facing the element passage member. The coating layers are not formed on surfaces of the laminate parallel to the laminating direction.

Abstract: A gas sensor control apparatus includes a heater regulating section to control the supply of electricity to a heater included in a gas sensor, an impedance sensing section to sense an impedance of a cell of the gas sensor, and an impedance condition examining section to examine whether the sensed impedance is greater than or equal to a predetermined abnormality judging threshold. The control apparatus further includes a voltage condition examining section to examine whether a maximum effective voltage is applied to the heater, when the impedance is above the predetermined abnormality judging threshold, a duration measuring section to examine whether an application time duration of the maximum effective voltage becomes equal to or longer than a predetermined heater overheat preventing time, and a voltage decreasing section to decrease the heater application voltage to such a lower effective voltage as to hold the temperature of the cell higher than or equal to 500° C.

Abstract: Method and apparatus for measurement of the oxygen partial pressure or the oxygen content in a measurement gas in at least one measurement cycle using a solid electrolyte cell having at least one oxygen-conducting solid electrolyte, and having at least one reference electrode as well as at least one measurement electrode, wherein the at least one measurement electrode is in communication with the measurement gas and the at least one reference electrode is in communication with a reference gas or reference volume separated from the measurement gas, wherein a current is imposed via the electrodes on the solid electrolyte cell for pump operation and a measurement voltage (UM) is tapped at the electrodes.

Abstract: A gas concentration detection device includes: a first sensor having a resistance layer exposed to a gas, and an electrode covered by the resistance layer, the first sensor producing an output according to a gas component ratio on the electrode surface; and a second sensor having a pump cell that pumps oxygen into a gas chamber that contains part of the gas or discharges oxygen out of the gas chamber, and a sensor cell that produces an output according to a gas component ratio in the gas within the gas chamber, the second sensor producing an output based on the pump cell current when the pump cell is operated such that the output of the sensor cell is a predetermined value; and a hydrogen concentration detection unit that detects a hydrogen concentration in the gas based on an output difference between the first sensor output and the second sensor output.

Abstract: Disclosed is a high sensitive gas sensor using a carbon material containing an ionized metal catalyst and a method of manufacturing the same. The method includes the steps of: (1) preparing a hydroxide solution by dissolving a hydroxide in a distilled water; (2) dissolving a metal catalyst in the hydroxide solution; (3) immersing the carbon material in a solution obtained through step (2) and stirring the carbon material; (4) heat-treating a mixture obtained through step (3); (5) cleaning the heat-treated carbon material obtained through step (4); (6) drying the carbon material cleaned through step (5); and (7) manufacturing the gas sensor by loading the carbon material obtained through step (6) on a substrate. The gas sensor having high sensitivity and responsiveness with respect to a target gas even in a normal temperature is obtained.

Abstract: A gas sensor, that represses a manufacturing cost, obtains high responsiveness and can effectively reduce adhesion of water to a sensor element and intrusion of water into the sensor element, is provided. In the gas sensor that has the sensor element mainly containing a solid electrolyte with oxygen ion conductivity and a protective cover arranged to surround the sensor element and detects a predetermined gas component in a measurement gas, the protective cover includes an inner protective cover that is formed into a bottomed cylindrical shape, has a plurality of inner gas distributing holes formed in two rows on its side surface in a longitudinal direction of the sensor element and surrounds one front end of the sensor element, and an outer protective cover that is formed into a bottomed cylindrical shape, has a plurality of outer gas distributing holes on its side surface and surrounds the inner protective cover.

Abstract: The gas sensor element includes an inner space into which a measurement gas is introduce through a diffusion resistor, a first oxygen pump cell, a second oxygen pump cell and a sensor cell. One of the electrodes formed on the opposite surfaces of the solid electrolyte body of the first oxygen pump cell and one of the electrodes formed on the opposite surfaces of the second oxygen pump cell are disposed opposite to each other across from the inner space. The other electrode of the first oxygen pump cell and the other electrode of the second oxygen pump cell are exposed to a common reference oxygen concentration gas.

Abstract: A gas sensor element includes an insulating ceramic base, a solid electrolyte body, and a heating element. The solid electrolyte body is disposed in an opening of the insulating ceramic base and has a measuring electrode affixed to one of major surfaces thereof and a reference electrode affixed to the other major surface. The measuring electrode is exposed to gas to be measured. The reference electrode is exposed to a reference gas. The heating element works to activate the solid electrolyte body and is mounted on one of opposed surfaces of the insulating ceramic base on the same side as the major surface of the solid electrolyte body on which the reference electrode is disposed. Specifically, the insulating ceramic base is located between the solid electrolyte body and the heating element, thereby ensuring a desired degree of electric insulation between the heating element and the reference electrode.

Abstract: Disclosed is an electrochemical gas sensor using micro electro mechanical systems (MEMS). The MEMS electrochemical gas sensor includes: a substrate a lower central region of which is etched by a predetermined thickness; a first insulation film formed on the substrate; a heat emitting resistance body formed on the first insulation film; a second insulation film formed on the heat emitting resistance body; a reference electrode formed in an upper central region of the second insulation film; a solid electrolyte formed on the reference electrode; and a detection electrode formed on the solid electrolyte.

Abstract: An ammonia gas sensor (200A) having an oxygen ion conductive solid electrolyte member (22A); a detection electrode (2A) and a reference electrode (4A) which are disposed on the solid electrolyte member; and an intermediate layer (5A) interposing between the detection electrode and the solid electrolyte member; wherein the intermediate layer contains the oxygen ion conductive solid electrolyte component in an amount of 50 wt % or more, and a first metal oxide which is an oxide of at least one metal selected from the group consisting of Co, Mn, Cu, Ni, and Ce, and the detection electrode contains Au in an amount of 70 wt % or higher and no first metal oxide.

Abstract: There is provided a control device for a gas sensor. The gas sensor is formed with first and second oxygen pumping cells to define first and second measurement chambers. Under the control of the sensor control device, the first and second oxygen pumping cells effect oxygen pumping actions against the first and second measurement chambers, respectively. The sensor control device is configured to detect currents through the first and second oxygen pumping cells, calculate a correction coefficient by comparison of a detection value of the first oxygen pumping cell current at a known oxygen concentration period with a previously stored reference value, correct the first oxygen pumping cell current by the correction coefficient and determine the concentration of nitrogen oxide in the gas under measurement based on the corrected first oxygen pumping cell current and the detected second oxygen pumping cell current.

Abstract: A gas sensor including a gas sensor element having a first measurement chamber (16); a first pumping cell (11); a second measurement chamber (18) into which a gas to be measured having a controlled oxygen partial pressure is introduced; and a second pumping cell (13) having a second inner pump electrode (13b) and a second counterpart electrode (13c) pump electrode configured to detect a specific gas component. The second inner pump electrode is made of a material that contains, as a principal ingredient, two kinds of Pt particles having different particle sizes and whose particle size ratio measured by a sedimentation particle-size distribution ranges from 1.75 to 14.2. A mixing ratio between large Pt particles and small Pt particles has a mass ratio of 10/90 to 50/50. A 10 kHz-1 Hz resistance value across the second pumping cell at 600° C. is 150? or less.

Abstract: A gas sensor including a pump electrode and a method for manufacturing a conductive paste for forming the pump electrode. When the pump electrode constituting an electrochemical pump cell for adjusting an oxygen partial pressure inside a gas sensor to measure a concentration of a gas component in a measurement gas by a current-limiting method is formed of a cermet of a noble metal and an oxide having oxygen ion conductivity, the noble metal contains a first noble metal having a catalytic activity, and a second noble metal having a catalytic activity suppressing ability to suppress the catalytic activity of the first noble metal with respect to an oxide gas except for oxygen, and an abundance ratio of the second noble metal with respect to the first noble metal in a particle surface of the first noble metal existing in the pump electrode is to be 0.01 to 0.3.

Abstract: A gas sensor for measuring NOx concentration in measurement gas based on sensor output depending on an amount of the detected oxygen includes an oxygen concentration control part for controlling oxygen concentration in the measurement gas. The oxygen concentration control part allows a control of oxygen concentration in the measurement gas to set at a designated value even after being mounted on an automobile, so that dependency of the sensor output with respect to oxygen concentration can be quantitatively detected. The sensor output for detecting NOx concentration is corrected by estimating an amount of a change accompanying the sensitivity degradation of the sensor output with respect to NOx concentration on the basis of a difference between oxygen output characteristics of the sensor output of an actually-used sensor and oxygen output characteristics of a sensor in the initial state, and correcting the sensor output in accordance with the amount of the change.

Abstract: The invention concerns a probe for measuring hydrogen comprising a probe body and a hydrogen sensor. The sensor body has a wall within which a sealed cavity is defined. The cavity contains a solid reference material for generating a reference partial pressure of hydrogen within the cavity. At least a portion of the wall of the cavity is formed from a solid electrolyte material carrying a measurement electrode on a surface of the solid electrolyte outside the cavity and a reference electrode on a surface of the solid electrolyte within the cavity, exposed to the reference partial pressure of hydrogen. An electrical conductor extends from the reference electrode through the wall of the cavity to an external surface of the sensor body. The probe body comprises a chamber for receiving the sensor and a reference-signal connection for connecting to the electrical conductor when the sensor is received in the chamber.

Abstract: A gas probe, in particular a lambda probe for the analysis of exhaust gases from a mobile internal combustion engine, includes at least one protective device, at least partly surrounding a sensitive sensor element of the gas probe, which comes into contact with a gas. The at least one protective device includes a gas contact face which at least partly has a hygroscopic surface.

Abstract: A gas sensor for detecting a predetermined gas component in a measurement gas includes a sensor element in which an opening of a first gas inlet and an opening of a second gas inlet for introducing the measurement gas from an outside are provided at one end. The openings are elongated and substantially rectangular. A sum of sizes in a lateral direction of the openings is greater than or equal to 8 ?m and less than or equal to 60 ?m, and a sum of areas of the openings is greater than or equal to 0.02 mm2 and less than or equal to 0.1 mm2. The sizes in the lateral direction and the areas of the openings are set to be within a preferable range so that the water droplets attached on the forward end surface can be prevented from entering into the sensor element through the openings.

Abstract: An exhaust gas sensor that simultaneously exhibits enhanced water soak resistance and functionality, that is multilayered and exposed to a space in an exhaust path. The exhaust gas sensor includes: an electrolyte layer, positioned between an exhaust electrode and an atmosphere electrode; an atmospheric layer formation layer formed toward the atmosphere electrode to form an atmospheric layer to which the atmosphere electrode is exposed; a porous diffusion resistance layer formed toward the exhaust electrode to control flow rate of an exhaust gas reaching the exhaust electrode; and a porous trap layer formed to cover the entire section exposed to the space in the exhaust path. The trap layer includes a first trap layer, which covers a region near a gas inlet/outlet section of the diffusion resistance layer, and a second trap layer, which covers another region that covered by the first trap layer. The first trap layer is thinner than the second trap layer.

Abstract: A sensor for specifying a concentration of a predetermined gas component in a measurement gas on the basis of a current flowing in an electrolyte by decomposition of the predetermined gas component, includes an internal space; a reference gas space; a pumping cell capable of pumping out oxygen in the internal space by applying a predetermined voltage between a first electrode and a second electrode; and a measuring cell including third and fourth electrodes and measuring a current flowing when a voltage is applied between the third electrode and the fourth electrode; wherein the first electrode is formed of porous cermet consisted of a noble metal and an oxygen ion conductive solid electrolyte, and the porosity of the first electrode is greater than or equal to 10% and less than or equal to 50%.

Abstract: A hydrogen gas sensor comprising a detection electrode, a reference electrode, and an electrolyte contacting with these electrodes, in which the reference electrode and the detection electrode are composed of a material having a property that hydrogen molecule doesn't voluntarily dissociate into atomic hydrogen on a surface of the electrode in Standard State such as nickel, titanium, copper, tungsten and the like, in which hydrogen gas is detected by an electromotive force generated between the reference electrode and the detection electrode while at least the detection electrode is maintained at a temperature not less than a temperature that hydrogen molecule begins to dissociate into atomic hydrogen voluntarily on the surface of the detection electrode.

Abstract: A sensor control device for controlling a current application state of a gas sensor element when measuring a specific gas component concentration in a gas to be measured using the gas sensor element, which sensor control device includes: at least one cell having a solid electrolyte body and a pair of electrodes; a sensor heating unit as defined herein; an oxygen reference pole generating unit as defined herein; a damage avoidance time elapse determining unit as defined herein; and a reference generation current application permitting unit as defined herein.

Abstract: A method and an article of an electrically conductive ceramic interconnect bonded to a compatible ceramic housing for an oxygen partial pressure sensor system. The interconnect includes a LaxSryAlzMn1?zO3 (LSAM) having a stoichiometry enabling good electrical conductivity at high temperatures and the LSAM also bonded to a yttria stabilized zirconia forming a stable and durable seal.

Abstract: An ammonia gas sensor including a reference electrode (320) is formed on the back surface of a solid electrolyte member (310), and a detection electrode (335) is formed on the front surface of the solid electrolyte member (310). A detection lead (350) is provided on the front surface of the solid electrolyte member (310) such that the detection lead (350) is connected to the detection electrode (335). An insulating layer (340), (380) is provided between the detection lead (350) and the solid electrolyte member (310), or on the detection lead (350).

Abstract: A system includes a filter, a sensor, a processor, and a memory. The filter can be coupled to an engine exhaust and can operate in an accumulating mode during which particulate matter (PM) from the engine is trapped and also operate in a regenerating mode during which PM in the filter is emitted. The sensor is coupled to a discharge port of the filter and has an output to provide a sensor signal based on a concentration of PM in the filtered exhaust. The processor is coupled to receive the sensor signal and operable to determine at least one of a base level for the sensor signal during the accumulating mode and a regenerate level for the sensor signal during the regenerating mode, and operable to determine a calibration value for the sensor using at least one of the base level and the regenerate level. The memory stores the calibration value.

Abstract: A gas sensor (200) has a gas sensor element (10) including a first measurement chamber (16); a first pumping cell (11) having a first interior pump electrode (11c) and its counterpart electrode (11b); a second measurement chamber (18); a second pumping cell (13) that has a second interior pump electrode (13b); and a beater (50). The heater (50) has a lead section (50a); a first resistance portion (50bx) having a higher resistance than the lead portion (50a); and a main heating portion (50k) having a second resistance portion (50by) having a higher resistance than the first resistance portion (50bx) disposed at a leading end side in a longitudinal direction relative to a leading end of the first resistance portion (50bx). The second interior pump electrode (13b) is located within the first resistance portion (50bx) in the longitudinal direction.

Abstract: An apparatus and methods are provided for the accurate determination of hydrogen content in fluid media at elevated temperatures. The apparatus consists of a proton conducting solid electrolyte in contact with an internal metal/hydrogen reference standard, in which the electrolyte and the reference material are in a chemically stable contact. The electrical signal generated is a function of the hydrogen concentration on the measuring side.

Abstract: A method is provided for activating a zirconia oxygen sensor which detects the oxygen concentration of an ambient atmosphere by means of a zirconia element that has a porous electrode formed on both sides of an impervious oxygen ion conductor. An electrical current is applied as a pulsed, square wave, direct current during heat up, heat soak, and cool down of the ionic conductor that is applied to ceramic substrate, thereby causing oxygen ions to flowing through the sensor body and pumping oxygen gas through the sensor electrodes, thus improving electrode porosity distribution.

Abstract: An oxygen sensor element 1 includes: a cup-shaped solid electrolyte body 10, inside of which a reference gas chamber 13 is provided; a measuring electrode 11 that comes into contact with measured gas; and a reference electrode 12. A heater 2 is disposed inside the reference gas chamber 13. The measuring electrode 11 is formed surrounding the outer surface 101 in a tip end section 100 of the solid electrolyte body 10. The reference electrode 12 is formed in a measuring-electrode-opposing-region 102a that is a region on the inner surface 102 of the solid electrolyte body 10 opposing the measuring electrode 11 with the solid electrolyte body 10 therebetween. The area S1 of the measuring electrode 11 and the area S2 of the reference electrode 12 satisfy a relationship 0.010?S2/S1<0.723.

Abstract: A gas sensor element for detecting a specific gas component contained in a gas to be measured includes: a solid electrolyte layer; a first electrode disposed on the solid electrolyte layer; a second electrode disposed on the solid electrolyte layer; and a porous layer disposed on one of the first electrode and the second electrode such that the gas to be measured is introduced from the outside of said gas sensor element and passes through the porous layer to at least one of the first electrode and the second electrode. The porous layer includes: a first porous layer including a first ceramic porous body which does not include noble metal particles dispersed therein; and a second porous layer provided on the first porous layer and including a second ceramic porous body and noble metal particles dispersed therein.

Abstract: A bifunctional total NOx and O2 sensor assembly with an internal reference for high temperature sensing. Two electrochemical total NOx(NO+NO2) measuring systems and method were coupled with a metal/metal oxide internal oxygen reference to detect O2 and NOx simultaneously in a combustion environment using a single sensor. A Pd/PdO-containing reference chamber was sealed within a stabilized zirconia superstructure by a high pressure/temperature bonding method. An amperometric and potentiometric NOx sensor assembly was built on the outside of the Pd/PdO chamber. Pt-loaded zeolite Y was used to obtain total NOx capacity and also to cover the Pt electrodes for detecting oxygen in the presence of NOx.

Abstract: A plural-cell gas sensor including at least an oxygen pump cell (40) comprising a solid electrolyte ceramic layer; an internal space (210) formed between the cells; and a heater substrate (190) arranged on the side of the oxygen pump cell; the heater substrate heating the oxygen pump cell that pumps oxygen out of the internal space.

Abstract: A sensor element is provided for determining at least one physical property of a gas mixture in at least one gas chamber, which includes at least one component to be identified, especially oxygen, and at least one oxidizable component, especially a combustion gas. The sensor element has at least one first electrode, at least one second electrode, and at least one solid electrolyte connecting the at least one first electrode and the at least one second electrode. The at least one second electrode has a lower catalytic activity, particularly a lower electrocatalytic activity with respect to the at least one oxidizable component than the at least one first electrode.

Abstract: A measuring sensor is described for determining a physical property of a measured gas, especially for determining the oxygen concentration or the pollutant concentration in the exhaust gas of internal combustion engines, which has a sensor element that is exposable to the measured gas which is at least partially coated with a protective layer that protects against harmful components in the measured gas. In order to achieve producing a “contamination protection”, that is cost-effective from a manufacturing technology point of view, particularly against silicon compounds and phosphorus compounds, the protective layer (26) is made of highly active ?- or ?-aluminum oxide (Al2O3) having additives of compounds of the alkaline metals group, the alkaline earths group, the IV B subgroup or the lanthanides group.

Abstract: A gas sensor control apparatus including internal resistance detection means for detecting an internal resistance value of one of cells of a gas sensor, concentration detection means for detecting a concentration value of a specific gas component in a gas to be measured and outputting the detected concentration value, heater current supply control means for controlling a current to be supplied to a heater of the gas sensor such that the detected internal resistance value becomes a target value, determination means for determining whether or not the detected internal resistance value is within a permissible range including the target value, nullification information generation means for generating nullification information to nullify the detected concentration value, when it is determined that the target value is out of the permissible range, and nullification information output means for outputting the nullification information to an external device connected to the gas sensor control apparatus.

Abstract: In a sensor diagnosis process, a controller for controlling an NOx gas sensor performs processing of changing the oxygen partial pressure in a second measurement chamber by changing the oxygen partial pressure in a first measurement chamber (S190), processing of detecting a current flowing through a second pump cell before the change of the oxygen partial pressure (S180), and processing of detecting a current flowing through the second pump cell after the change of the oxygen partial pressure (S230). Furthermore, the controller performs processing of judging whether or not the ratio between the current values detected by the respective current detecting unit falls within an allowable range, judging that the second pump cell 113 is in a normal state if the ratio between the current values falls within the allowable range, and judging that the second pump cell 113 is in a deteriorated state if the ratio between the current values is out of the allowable range (S240 and S250).

Abstract: A sensor element is used to detect a physical property of a measuring gas, preferably to determine the oxygen content or the temperature of an exhaust gas of an internal combustion engine. The sensor element contains a first solid electrolyte layer and a second solid electrolyte layer. A first printed conductor and a second printed conductor are provided on opposite sides of the first solid electrolyte layer, the first printed conductor including a first electrode and a feed line to the first electrode, and the second printed conductor including a second electrode and a feed line to the second electrode. A third printed conductor, which includes a third electrode and a feed line to the third electrode, is provided on the second solid electrolyte layer. The second printed conductor is positioned between the third electrode and the first printed conductor.

Abstract: A noble metal catalyst powder produced by using co-precipitation method is made of noble metal alloy particles containing Pa, Pd, and Rh. The noble metal alloy particles have an average particle size within a range of 0.2 ?m to 2.0 ?m. A standard deviation in content of each of Pa, Pd, and Rh is not more than 20 mass %. This standard deviation in content of each of Pa, Pd, and Rh is detected at not less than ten detection-points of the noble metal catalyst powder by quantitative elemental analysis. A gas sensor element has the noble metal catalyst powder. An A/F sensor is equipped with the gas sensor element using the noble metal catalyst powder.

Abstract: A sensor control apparatus comprising an air/fuel ratio sensor having a sensor cell with a pair of electrodes, a current source capable of supplying a predetermined current between the electrodes, a current control section that turns on/off the current source, a voltage detecting section that detects voltages generated between the electrodes at respective times when the current source is turned on and off, a differential voltage detecting section that detects a differential voltage between the voltages that are generated at the respective times when the current source is turned on and off, a first voltage comparing section that compares the differential voltage with a first threshold voltage, and a half-activated state determining section that determines that the sensor cell has reached a half-activated state when the differential voltage is lower than the first threshold voltage. A sensor control method is also provided.

Abstract: A sensor element for determining a physical property of a gas in a measuring gas chamber includes at least two electrodes, at least one solid-state electrolyte connecting the electrodes, and at least one heating element having at least two heating contacts. A first heating contact and a first electrode are contacted via a common connecting line, and a second heating contact and a second electrode are connected to a common ground line.

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: An oxygen sensor generating an accurate output concerning low-concentration exhaust gas positioned downstream of a three-way catalyst. The oxygen sensor includes an exhaust gas side electrode exposed to an exhaust gas; a reference gas side electrode exposed to a reference gas serving as a reference for oxygen concentration; and an electrolyte positioned between the exhaust gas side electrode and the reference gas side electrode. Further, a reduction mechanism positioned toward a front surface of the exhaust gas side electrode ensures the ratio of the amount of exhaust gas introduced to the exhaust gas side electrode to the amount of an exhaust gas flow to the outside of the oxygen sensor is smaller than the ratio of the amount of exhaust gas introduced to an electrode for the air-fuel ratio sensor to the amount of an exhaust gas flow to the outside of the air-fuel ratio sensor.

Abstract: A gas sensor element has a solid electrolyte of an oxygen ion conductivity, a target gas electrode formed on one surface of the solid electrolyte, a reference gas electrode formed on the other surface of the solid electrolyte, a porous diffusion resistance layer through which the target gas passes to reach the target gas electrode, and a catalyst layer formed on an outer surface of the porous diffusion resistance layer. The target gas electrode is formed around the porous diffusion resistance layer. The catalyst layer contains noble metal catalysts. The noble metal catalysts contain at least rhodium and palladium. A content of rhodium is not less than 10 mass % and a content of palladium is not less than 20 mass % to the entire of the noble metal catalysts.

Abstract: A gas concentration detecting system has a first cell generating electric current at first oxygen sensitivity, a second cell generating current at second oxygen sensitivity and a reference cell generating current at reference oxygen sensitivity. The cells have the same structure except that the second cell has a catalyst layer for removing hydrogen as from measured gas containing oxygen gas. The system determines first corrected current from current of the first cell exposed to measured gas, current of the first cell exposed to inspection gas containing oxygen gas at reference concentration and reference cell current of the reference cell exposed to inspection gas, determines second corrected current from current of the second cell exposed to measured gas, current of the second cell exposed to inspection gas and the reference cell current, and detects concentration of hydrogen gas in measured gas from the corrected currents.

Abstract: A sensor element for determining at least one physical property of a gas mixture is provided. The sensor element has at least one first electrode and at least one second electrode, and at least one solid electrolyte that connects the at least two electrodes. The at least one first electrode is connected via at least one diffusion-resistance element to the at least one gas chamber and/or to at least one reference chamber. The at least one second electrode is connected via at least one flow-resistance element to the at least one gas chamber. The at least one flow-resistance element and the at least one diffusion-resistance element are designed in such a way that the limit current of the at least one first electrode is smaller than the limit current of the at least one second electrode.

Abstract: In an activation state of a sensor device, when voltage on the connection points between the sensor device and the sensor control circuit becomes a preset abnormal value, electric cut off is made between the sensor control circuit and the connection point. Then, the delivery of power to the heater is ceased to lower the temperature of the cells to a below of an activation temperature, thereby increasing the internal resistance of the cell. Thereafter, the sensor control circuit supplies to the sensor device a current in a degree not to damage the sensor device, to detect voltages on the connection points at that time. By comparing between the voltages on the respective connection points detected, a content and location of abnormality occurred is identified for the sensor device.

Abstract: An oxygen sensor includes a base body portion; and a plurality of function layers laminated on a surface of the base body portion. The function layers includes a solid electrolyte layer adapted to conduct oxygen ions; a reference electrode layer located on a base body portion side of the solid electrolyte layer; a sensing electrode layer located on the opposite side of the solid electrolyte layer to the reference electrode layer; a heater portion adapted to activate the solid electrolyte layer by heating; and a gas diffusion layer formed between the reference electrode layer and the base body portion, and adapted to diffuse a reference gas within the gas diffusion layer. The gas diffusion layer is formed to have a porosity indicating a limit current value ranging between 60 ?A and 200 ?A.

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 0.3 and less than 0.7.

Abstract: An interface device for a gas sensor includes a detection resistor having first and second ends to generate voltages by a current output of the gas sensor, a differential amplifier having first and second input terminals to receive the voltages of the first and second resistor ends and an output terminal to output a voltage according to a difference between the voltages of the first and second resistor ends, a first switching element to transmit the voltage of the first resistor end to the first input terminal of the differential amplifier in a transmission state and interrupt transmission of the voltage of the first resistor end to the first input terminal of the differential amplifier in an interruption state and a second switching element turned on to establish continuity between the first and second input terminals of the differential amplifier when the first switching element is in the interruption state.

Abstract: A micro fuel cell sensor having laminated gas permeable membrane. The sensor comprises a housing, first and second gas diffusing electrodes spaced from one another, a fuel-cell spacer having an acidic electrolyte disposed between said first and second electrodes, and two gas permeable membranes. The first gas permeable membrane comprises a polymer laminated on a metal substrate, wherein the substrate comprises pores that have dimensions at least less than one-half the thickness of the polymer film.

Abstract: A method and system for improving sensor accuracy of diesel emissions is disclosed. The method and system comprises changing the sensor reading as a function of sensor age to provide a more accurate measure of the diesel emissions. By estimating the degree of sensor error and then providing a gain correction factor as a function of sensor age, a more accurate measure of the diesel emissions is provided.