Abstract: A crimp contact, a gas sensor including the crimp contact for outputting a signal from a sensing portion of a sensor element to an external device, and a method for manufacturing the crimp contact. The crimp contact includes a barrel portion crimped so as to fix a plurality of lead core wires (16) of an electrical lead connected to the external device. A hold portion constituting the barrel portion is formed such that the lead core wires 16 of the electrical lead are disposed in an U-shaped hold portion 77 so as to be crimped between an anvil 120 and a crimper 121. An outer surface of the U-shaped hold portion 77 has a plating layer 85 thereon to thereby constantly secure slidability between a sliding face of the crimper 121 and the outer surface of the U-shaped hold portion 77.

Abstract: A control apparatus (100) for a gas sensor (10) which includes a cell (2) composed of a solid electrolyte body and a pair of electrodes provided thereon. The control apparatus includes voltage application means (70) for applying a single pulse voltage to the cell over a constant energization time T; first-output-value obtaining means 70 for obtaining a first output value Vri1 from the cell when a first time t1 shorter than the constant energization time has elapsed; second-output-value obtaining means (70) for obtaining a second output value Vri2 from the cell when a second time t2 shorter than the constant energization time but longer than the first time has elapsed; and deterioration-degree detection means 70 for detecting the degree of deterioration of the cell on the basis of a difference ?Vri between the second output value and the first output value.

Abstract: A gas sensor element has a first cell, a second cell, and a solid electrolyte layer having proton conductivity commonly used by the first cell and the second cell. The first cell has a first cathode and a first anode exposed to the target detection gas containing hydrogen atoms. The second cell has a second anode, a second cathode, and a shield layer with which the second anode is covered. A voltage is supplied to the first and second cells. A gas concentration of the target detection gas is calculated on the basis of a difference between a current of the first cell and a current of the second cell because the current in the first cell is a sum of proton conductivity current and an electron conductivity current. The current in the second cell is an electron conductive current only.

Abstract: A method for determining a flux of a gas contained in a medium through a boundary of the medium comprises 1) measuring at least twice with a probe a concentration C of the gas over a time interval ?t and 2) determining the flux of the gas using the following mathematical equation: (I) where F is the gas flux, D is the diffusivity value and ?C is a variation in the gas concentration during the time interval ?t. The probe is placed proximate the boundary. The probe has a gas inlet, a cavity, a gas concentration sensor and a membrane. Each element is in fluid communication with each other so that the gas flows from the gas inlet through the membrane and contacts the gas concentration sensor.

Abstract: A gas sensor comprises a substrate layer; a pair of interdigitated metal electrodes, said electrodes include upper surfaces, the electrodes selected from the group consisting of Pt, Pd, Au, Ir, Ag, Ru, Rh, In, Os, and their alloys. A first layer of solid electrolyte staying in between electrode fingers and partially on said upper surfaces of said electrodes, said first layer selected from NASICON, LISICON, KSICON and ??-Alumina. A second layer of metal carbonate(s) as an auxiliary electrolyte engaging said upper surfaces of the electrodes and the first solid electrolyte. The metal carbonates selected from the group consisting of the following ions Na+, K+, Li+, Ag+, H+, Pb2+, Sr2+, Ba2+, and any combination thereof.

Abstract: A device for determining the CO concentration in a gas containing hydrogen is provided, including a detection electrode in contact with the gas, and a counter electrode, each being in contact with an electrolyte; a current source to deliver a current with a predetermined intensity between the detection electrode and the counter electrode so as to generate, at the detection electrode, an electric potential fluctuating between two threshold values due to the adsorption and desorption of the CO at the detection electrode; a device for measuring the potential; and a calculating device to determine the CO concentration, connected to the current source and to the device for measuring the potential, for calculating a characteristic parameter of the fluctuations of the potential, and for determining the CO concentration from the calculated characteristic parameter and the intensity of the applied current.

Abstract: A gas sensor control apparatus is provided which controls an operation of a gas sensor made up of a solid electrolyte body and a pair of electrodes to output a signal indicating the concentration of a given gas component contained in gas. The gas sensor control apparatus includes a constant current circuit that is connected electrically to one of the electrodes of the gas sensor and supplies a constant current thereto and a controller. The controller supplies a constant current to the gas sensor so that it flows from one of the electrodes to the other in a selected direction, thereby changing a response time the gas sensor takes to react to a change in concentration of the gas component. This results in an increased accuracy, for example, in controlling an air-fuel ratio of a mixture to an internal combustion engine in an engine control system.

Abstract: A gas sensor including a gas sensor element that extends in an axial direction and has a detection section at a front-end side thereof, and an electrode pad at a rear-end side thereof; a connection terminal that is electrically connected to the electrode pad; and an insulated separator that extends along the axial direction and has an inserting hole into which the connection terminal is inserted. An element side section is arranged within the inserting hole and is connected the electrode pad, and an external circuit side section extends further to the outside in a diametrical direction than an outer surface of the separator through one or more first bending sections from the element side section.

Abstract: A system for estimating gas concentrations in a mixed atmosphere includes (a) a plurality of sensors for providing a set of measurements, at least one of the sensors sensitive to an internal concentration of hydrogen; and (b) a processor for receiving the set of measurements and for executing a sequential estimation filter that includes a plurality of states having a corresponding set of values. The processor responsively adjusts at least a portion of the set of values in response to the set of measurements. The plurality of sensors can include a resistive sensor and a capacitive gas sensor, both of which are sensitive to hydrogen concentration. The plurality of states can include states representative of hydrogen pressure in the mixed atmosphere, hydrogen concentration in a bulk material of at least one of the sensors, and hydrogen concentration in an interface layer of at least one of the sensors.

Abstract: A marine engine exhaust system has an exhaust conduit conveying engine exhaust gas from upstream to downstream, a sensor sensing oxygen content of the exhaust gas in the conduit, and a shield located in the conduit. The shield is configured to shield the sensor from deleterious effects of liquid when liquid and exhaust gas is reverted in the exhaust conduit from downstream to upstream.

Abstract: A gas sensor system including a gas sensor; a current control unit; a constant control unit; and a temperature acquisition unit. The gas sensor includes a measurement chamber, a pump cell and an electromotive force cell. The current control unit performs feedback control on current flowing through the pump cell in response to the voltage of the electromotive force cell and in accordance with a control constant which characterizes the feedback control. Further, the constant control unit changes the control constant of the feedback control in accordance with a value (for example, a resistance value of the electromotive force cell) corresponding to the temperature of the gas sensor.

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: A deterioration signal generation device for an oxygen sensor having a power supply different than a power supply connected to an external device, including a connection unit for electrically connecting the ground lines of the respective power supplies; a first acquisition unit for electrically connecting to a first output line at a reference potential side and to a second output line at a sensor potential side of the oxygen sensor, to obtain first and second potentials, respectively; an operation unit that calculates a first differential value between the first and second potentials; a processing unit that performs an operation on the first differential value; a second acquisition unit that acquires a third potential of a first input line at a reference potential side of the external device; and an output unit that generates the deterioration signal by superposing the second differential value on the third potential.

Abstract: A deterioration signal generation device for an oxygen sensor having a power supply different than a power supply connected to an external device, including a connection unit for electrically connecting the ground lines of the respective power supplies; a first acquisition unit for electrically connecting to a first output line at a reference potential side and to a second output line at a sensor potential side of the oxygen sensor, to obtain first and second potentials, respectively; an operation unit that calculates a first differential value between the first and second potentials; a processing unit that performs an operation on the first differential value; a second acquisition unit that acquires a third potential of a first input line at a reference potential side of the external device; and an output unit that generates the deterioration signal by superposing the second differential value on the third potential.

Abstract: Methods systems and device for detecting humidity in air through use of an ammonia sensor included in the exhaust of an engine, such as a diesel engine are provided. In one example, a method for an engine having an exhaust with an ammonia sensor includes adjusting an operating parameter in response to ambient humidity, the ambient humidity based on a first ammonia sensor reading at a first exhaust air-fuel-ratio and a second ammonia sensor reading at a second exhaust air-fuel-ratio.

Abstract: A method for determining a lambda air ratio using a gas sensor having a ceramic measuring element, an output voltage of the gas sensor changing abruptly if lambda is changed in the range around lambda=1 and the gas sensor having an initial inverse voltage which is dependent on the temperature of the gas sensor. A threshold value for the initial inverse voltage is established for a limit between a lambda value below and above 1 as a function of the temperature of the gas sensor. Also described is a device for implementing the method. The method and the device make it possible to operate gas sensors having a ceramic measuring element at an even lower temperature than according to the related art and thus reduce the period between the start of an internal combustion engine and the operational readiness of a lambda regulation. This makes it possible to reduce the fuel consumption as well as the emission of undesirable components of the exhaust gas.

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: A gas sensor including a sensor element constituted by an oxygen-ion conductive solid electrolyte as a main component and detecting a predetermined gas component in a measurement gas includes: an external communication part having an opening opened to the outside, and introducing the measurement gas from the outside under a predetermined diffusion resistance; an internal space communicating with the external communication part; a first electrode formed on a surface of the internal space; a second electrode formed in a space different from the internal space; and a pumping cell operable to pump out oxygen existing in the internal space when a predetermined voltage is applied between the first electrode and the second electrode. The thickness of the external communication part is 50% or more and 100% or less of the thickness of the internal space.

Abstract: A method and device allow the determination of the concentrations of a plurality of gas species in a gas mixture based on the output signals from a plurality of gas sensors, each of which is sensitive to a plurality of gas species in the gas mixture. The method includes measuring the response of each sensor at a number of levels of each gas in the mixture, determining a mathematical representation of the response characteristics of each sensor, and using the mathematical representation to determine gas concentrations from sensor readings.

Abstract: An array-type sensor that senses NH3 includes non-Nernstian sensing elements constructed from metal and/or metal-oxide electrodes on an O2 ion conducting substrate. In one example sensor, one electrode may be made of platinum, another electrode may be made of manganese (III) oxide (Mn2O3), and another electrode may be made of tungsten trioxide (WO3). Some sensing elements may further include an electrode made of La0.6Sr0.4Co0.2Fe0.8O3 and another electrode made of LaCr0.95Mg0.05O3.

Abstract: A gas sensor element with a bottom part is composed of at least a solid electrolyte body of oxygen ion conductivity, a reference electrode, a detection electrode, an electrode protection layer which supports noble metal catalyst, and a heater. The electrode protection layer is composed of a covering layer, a catalyst layer and a poisoning layer. A quantity of the noble metal catalyst supported in the electrode protection layer at the bottom part of the gas sensor element is larger than that in the electrode protection layer at a leg part of the gas sensor. The bottom part of the gas sensor element has a high temperature rising speed more than the leg part when the heater generates heat energy.

Abstract: Methods and systems for diagnosing a multiple cylinder engine are provided herein. An exemplary method of diagnosing an internal combustion engine system having a multi-cylinder internal combustion engine is described. In one example, cylinder air-fuel imbalance is determined from the squared value of a difference of two values.

Abstract: There is provided a gas sensor element, including a solid electrolyte layer, a pair of sensor electrodes arranged on a front side of the solid electrolyte layer, a pair of sensor leads arranged on a rear side of the solid electrolyte layer and connected to the respective sensor electrodes; and insulating layers, one of which is arranged between one of the sensor leads and the solid electrolyte layer and the other of which is arranged between the other sensor lead and the solid electrolyte layer. The sensor electrodes have rear end portions located on the insulating layers and overlapping front end portions of the sensor leads, respectively. The sensor leads are denser than the sensor electrodes and have front ends located in the same positions as or positions rear of front ends of the insulating layers, respectively. There is also provided a gas sensor with such a gas sensor element.

Abstract: Provided are a method and an apparatus of controlling a flow rate of a primary recirculating exhaust gas in an oxyfuel combustion boiler, capable of realizing a stable combustion by a burner in oxyfuel combustion. Weight ratio of flow rate of primary recirculating exhaust gas [ton/h] to amount of pulverized coal from a mill [ton/h] is defined as G/C, and the flow rate of primary recirculating exhaust gas is controlled so that the G/C falls within a given range.

Abstract: Provided are a method and an apparatus of controlling exhaust gas in an oxyfuel combustion boiler which can attain stable combustion of the boiler while an amount of unburned combustibles and a NOx density in exhaust gas are maintained in their allowable ranges. A rate of supply of directly supplied oxygen to burners 6 to a total amount of oxygen produced by an air separation unit 18 is regulated in an operating range where the NOx density in the exhaust gas is below a NOx limit value and the amount of unburned combustibles in the exhaust gas is blow an unburned combustible limit value to thereby attain stable combustion of the oxyfuel combustion boiler.

Abstract: Disclosed herein is a method of making a sensing element comprising forming an electrically conductive element, wherein the sensing element comprises a metal selected from the group consisting of Pd and alloys and combinations comprising Pd; and wherein the electrically conductive element is thermally stable at temperatures as high as 1,200° C.

Abstract: An electrochemical gas sensor includes: a disc-shaped metal bottom member; a cylindrical metal side member that extends along the axial direction of the bottom member to surround the bottom member; a ring-shaped polymer gasket that includes an opening in the center and in which both sides of the opening each have an L-shaped member in cross section, with one section of the L-shaped member being in contact with the inner side of the side member and the other section of the L-shaped member being in contact with the bottom member; a gas sensor body that is located in the opening of the gasket and whose bottom surface is in contact with the bottom member and that includes a pair of electrodes and a solid electrolyte membrane or a separator retaining a liquid electrolyte; and a metal cover that is in contact with the top surface of the gas sensor body.

Abstract: An exhaust gas sensor device for detecting a concentration of at least one exhaust gas component in the exhaust gas line of an internal combustion engine is described, having at least one ChemFET for detecting the oxygen content of the exhaust gas. In addition, a corresponding engine control device and an engine control method are described.

Abstract: An oxygen measuring apparatus (500) includes an inlet pipe (506) having a first end and a second end, an oxygen sensor (511) arranged inside the inlet pipe (506) between the first end of the inlet pipe and the second end of the inlet pipe, the oxygen sensor (511) having a communication medium (515) disposed thereon and extending through the second end of the inlet pipe (506), a filtering medium arranged (505) inside the inlet pipe between the oxygen sensor (511) and the first end of the inlet pipe, a housing (501) arranged against the second end of the inlet pipe, and a sensor control interface (512) arranged within the housing (501) and in communication with the communication medium (515) of the oxygen sensor (511).

Abstract: A server rack includes a main body, an electronic scale, and an alarm. The main body is used for receiving a number of servers. The electronic scale includes a pressure sensor and a microcontroller. The main body presses on the pressure sensor so that the pressure sensor can measure the pressure from the main body to obtain a pressure signal. The microcontroller analyzes the pressure signal to calculating the total weight of the main body and the servers. The alarm stores a predetermined weight threshold, which is the total weight of the main body and the maximum servers that the main body can bear. The alarm also compares the measured total weight with the predetermined weight threshold. When the measured total weight is larger than the predetermined weight threshold, the alarm alarms.

Abstract: An ammonium gas sensor is provided. The ammonium gas sensor includes: a solid electrolyte layer having oxygen ion conductivity; a detection electrode formed on one surface of the solid electrolyte layer; a reference electrode that is a counter electrode of the detection electrode; a selective reaction layer covering the detection electrode; and a protection layer covering the selective reaction layer and made from a porous material; wherein the detection electrode includes a noble metal as a main component; the selective reaction layer includes oxide represented by AxMyOz as a main component, where A is one or more kind(s) of metal, M is vanadium, tungsten, or molybdenum and x, y, z are atomic ratios; and the protection layer includes the oxide that is in an amount smaller than a content of the oxide included in the selective reaction layer.

Abstract: Methods systems and device for detecting humidity in air through use of an ammonia sensor included in the exhaust of an engine, such as a diesel engine are provided. In one example, a method for an engine having an exhaust with an ammonia sensor includes adjusting an operating parameter in response to ambient humidity, the ambient humidity based on a first ammonia sensor reading at a first exhaust air-fuel-ratio and a second ammonia sensor reading at a second exhaust air-fuel-ratio.

Abstract: A sealing portion is formed of a calcined body that is made by calcining a powder compact of a spherically-shaped granulated powder that is selected from the group consisting of alumina, aluminum titanate and cordierite. Anisotropy in physical properties is less likely to occur in the powder compact, because these ceramics are not only good in terms of thermal stability but also their spherically-shaped granulated powders are less likely to be oriented at the time of powder compacting. Therefore, the sealing portion comes to have a long longevity, because slippages between the particles are less likely to occur even when thermal histories are applied thereto, and because it can maintain the gas sealing property stably for a long period of time.

Abstract: A detecting apparatus that detects an abnormality of imbalance of air-fuel ratios among cylinders of a multi-cylinder internal combustion engine, which is equipped with a variable working angle mechanism of an intake valve, the detecting apparatus includes an abnormality detection portion that detects a parameter regarding rotational fluctuations of each of the cylinders and detects whether or not there is an abnormality of imbalance of air-fuel ratios among the cylinders. The abnormality detection portion refrains from determining that the air-fuel ratios are normal when the working angle at the time of detection of the parameter is within a predetermined large working angle range, and determines that the air-fuel ratios are normal when the working angle at the time of detection of the parameter is within a predetermined small working angle range that is on a small working angle side with respect to the large working angle range.

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: 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: A method of controlling fuel composition learning includes steps of monitoring changes in airflow within an engine to determine steady state conditions. The method further includes steps of initiating a fuel composition learning process during steady state conditions. A current fuel component concentration factor is updated using a temporary fuel component concentration factor. The temporary fuel component concentration factor is calculated as the average of an air/fuel correction factor. Once the current fuel component concentration factor is updated, the temporary fuel component concentration factor is reset. The air/fuel correction factor is reset to reflect any difference that existed between the temporary fuel component concentration factor and the air/fuel correction factor at the update time.

Abstract: A system according to the principles of the present disclosure includes an error period module and a sensor diagnostic module. The error period module determines an error period based on an amount of time that a first air/fuel ratio and a desired air/fuel ratio are different. A first oxygen sensor generates a first signal indicating the first air/fuel ratio. The sensor diagnostic module diagnoses a fault in the first oxygen sensor when the error period is greater than a predetermined period.

Abstract: A gas sensor including a detection element having a stacked structure configured to detect a specified gas component contained in a gas to be detected. The detection element includes: a sensing portion including one or more solid electrolyte layers containing a first material as a main component and having a first surface and a second surface opposite the first surface; a first portion stacked on the first surface and including one or more first base layers containing a second material as a main component different from the first material; and a second portion stacked on the second surface and including one or more second base layers containing the second material. A total thickness of the one or more second base layers in a stacking direction is not less than 80% but not more than 120% of a total thickness of the one or more first base layers.

Abstract: In a method for operating a lambda sensor disposed in an exhaust gas system of an internal combustion engine,—the heating element is subjected to a predefined heating power substantially with the start of the engine;—during the heating process, the sensor signal is detected and compared to a threshold value specified for a lean and/or rich fuel/air mixture ratio, wherein the threshold value correlates with a sensor temperature, which is below the water ingestion critical temperature, and to a valid lambda signal,—when one of the specified threshold values is reached for the first time, a measured variable correlating with the sensor temperature is determined and the lambda signal is set as valid and forwarded, and—the determined measured variable correlating with the sensor temperature is transferred to a closed heating element control loop as a target value that corresponds to a target temperature.

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, and nullification setting means for setting the detected concentration value to a predetermined nullification concentration value to nullify the detected concentration value, when it is determined that the target value is out of the permissible range.

Abstract: It is an object of the present invention to provide a gas concentration detection apparatus that is capable of forming an accurate activity judgment when a gas concentration detection cell begins to detect gas concentration with high accuracy. When warm-up begins at time t0 in a NOx concentration detection apparatus that achieves NOx concentration detection with a NOx sensor cell after excess oxygen is discharged by an oxygen pump cell, a NOx sensor cell output begins to rise at time t1. Subsequently, at time t2, an oxygen pump cell output begins to rise. An inflection point appearing in the NOx sensor cell output is then located. At time t5 at which the inflection point appears, an activity judgment about the NOx sensor cell is formed.

Abstract: An inter-cylinder air-fuel ratio imbalance determination apparatus (determination apparatus) according to the present invention obtains, based on the output value of the air-fuel ratio sensor, an imbalance determination parameter which becomes larger as an air-fuel ratio fluctuation of an exhaust gas passing through a position at which the air-fuel ratio sensor is disposed becomes larger, during a parameter obtaining period. The determination apparatus energizes the heater of the air-fuel ratio sensor in such a manner that a temperature of the air-fuel ratio element during the parameter obtaining period is higher than a temperature of the air-fuel ratio element during a period other than the parameter obtaining period. Accordingly, the imbalance determination parameter is obtained while the responsiveness of the air-fuel ratio sensor is high, and thus, the inter-cylinder air-fuel-ratio imbalance determination having a high accuracy can be made.

Abstract: In an internal-combustion-engine control apparatus provided with an exhaust gas sensor control device that outputs a detection signal detected by an exhaust-gas sensor, while switching amplification factors of an amplification circuit or offset voltages of an offset circuit, it is determined whether the exhaust-gas sensor is in an activation state or not, and an electric current flowing into the exhaust-gas sensor is stopped, in the case where it is determined that the exhaust-gas sensor is in a non-activation state; the amplification factors of the amplification circuit are switched so that there is detected an air-fuel ratio signal at the time when an electric current flowing into the exhaust-gas sensor is stopped, and it is determined whether or not the offset circuit is abnormal, based on whether the respective air-fuel ratio signals at the amplification factors are within a predetermined range.

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 method and apparatus for controlling a multi-gas sensor, including an NOX sensor section and an ammonia sensor section. The NOX sensor section includes a first pumping cell adapted to pump oxygen into or out of a gas under measurement introduced into a first measurement chamber, and a second pumping cell communicating with the first measurement chamber and configured such that a second pumping current Ip2 corresponds to an NOX concentration of the gas under measurement. Oxygen concentration is calculated on the basis of a first pumping current flowing through the first pumping cell, and a corrected ammonia concentration is calculated on the basis of the oxygen concentration and the ammonia concentration output of the ammonia sensor section.

Abstract: A gas sensor includes a substantially cylindrical metal shell; a laminated sensor element held within the metal shell, and including a plate-shaped solid electrolyte layer extending in a longitudinal direction; an electrode portion provided on the solid electrolyte layer; an insulating layer; and a lead portion connected with the electrode portion, extending in the longitudinal direction, and having a front end portion laminated on the solid electrolyte layer, and a rear end portion laminated through the insulating layer on the solid electrolyte layer. The insulating layer has an end portion over and across which the lead portion extends, and which has a recessed shape, a raised shape, or a recessed and raised shape in the longitudinal direction as viewed in the lamination direction.

Abstract: This disclosure provides a method of detecting a cylinder-to-cylinder gap abnormality of an air fuel ratio with sufficient accuracy according to an individual specificity of an air fuel ratio detecting module. Particularly, the method may be used for an engine to detect the cylinder-to-cylinder gap abnormality of the air fuel ratio of supplied air fuel mixture abnormality based on an output value of a linear O2 sensor. Under a first predetermined condition, an output characteristic of the sensor is measured. The measured output characteristic is compared with a reference characteristic set in advance to calculate a correction value for correcting the sensor output according to the individual specificity of the sensor. Subsequently, under a second predetermined condition, the sensor output value is corrected based on the calculated correction value to detect the abnormality based on the corrected output value of the sensor.

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.