Abstract: An exhaust gas sensor includes an element cover, a heater, a heater control section, and a cover state diagnosing section. The element cover accommodates a sensor element including a detection section and includes one or more gas flow holes. The heater heats the sensor element. The heater control section controls how the heater heats the sensor element. The cover state diagnosing section diagnoses a state of the element cover using heater information obtained when the heater is operated by the heater control section. The cover state diagnosing section includes a diagnosability determining section, which determines whether the state of the element cover is diagnosable based on an accuracy of the heater information obtained from an operating state of the heater and a surrounding environmental state of the element cover.

Abstract: Various embodiments of the teachings herein may include a method for operating an internal combustion engine having probe measuring a gas concentration of a gas mixture, said probe comprising a pump electrode, comprising: controlling a first pump current at the pump electrode to provide a resulting first pump voltage; controlling a second pump current at the pump electrode to provide a resulting second pump voltage, wherein the second pump voltage is greater than the first pump voltage; calculating an aging factor for the probe on the basis of the first pump current and the second pump current; and adapting operation of the internal combustion engine based on a characteristic of the probe corresponding to the calculated aging factor.

Abstract: An internal combustion engine comprises an exhaust purification catalyst and a downstream side air-fuel ratio sensor which is arranged at a downstream side of the exhaust purification catalyst. A control system can perform fuel cut control which stops the feed of fuel to the internal combustion engine during operation of the internal combustion engine, and, after the end of fuel cut control, performs post-return rich control which sets the exhaust air-fuel ratio to a rich air-fuel ratio.

Abstract: Methods and systems are provided for diagnosing an intake oxygen sensor. In one example, a method may include indicating degradation of an intake oxygen sensor based on a first time constant of an output of the intake oxygen sensor and a second time constant of an output of a throttle inlet pressure sensor. The method may further include adjusting EGR flow based on the output of the intake oxygen sensor and the output of the throttle inlet pressure sensor when the intake oxygen sensor is not degraded.

Abstract: A particulate matter detecting apparatus that measures an amount of particulate matter in a gas by applying a predetermined voltage between a pair of first electrodes of a sensor element portion includes a detecting portion that detects whether more particulate matter than a reference amount has accumulated on the first electrodes, a temperature controlling portion that controls a temperature of the sensor element portion to become equal to or higher than a reference temperature when it is detected that more particulate matter than the reference amount has accumulated, and a voltage controlling portion that applies a reference voltage between the first electrodes and a second electrode arranged such that a solid electrolyte is sandwiched between the second electrode and the first electrodes, when it is detected that more particulate matter than the reference amount has accumulated.

Abstract: In a control device for an internal combustion engine including an air-fuel ratio sensor that includes a catalyst layer that covers an exhaust gas-side electrode, an oxygen storage capacity of the catalyst layer is acquired based on a sensor output of the air-fuel ratio sensor. The sensor output is corrected if the oxygen storage capacity is higher than a predetermined value and the sensor output is in a predetermined range in the vicinity of the theoretical air-fuel ratio. Preferably, the oxygen storage capacity is calculated by integrating the product of a deviation amount ?A/F of the sensor output with respect to the theoretical air-fuel ratio and a dwell time thereof. A correction period in which a correction operation is performed is set based on the oxygen storage capacity.

Abstract: A signal from a linear lambda probe, which signal is meant to represent an air/fuel ratio for the gas flowing in the exhaust section, specifically prior to combustion of said gas, is determined based on a pump current. A difference signal is formed based on a difference between a pump voltage signal and a Nernst voltage signal. An offset error in the measured signal is determined based on the difference signal for an approximately stoichiometrically prescribed raw setpoint value for the air/fuel ratio, with a setpoint value for the air/fuel ratio being determined based on the raw setpoint value and a forced excitation signal.

Abstract: A method of processing a sensor element includes the steps of: (a) preparing a gas atmosphere containing hydrocarbon, having an air-fuel ratio of 0.80 to 0.9999, and having a small amount of oxidizing gas added thereto; and (b) subjecting a sensor element to a heat treatment in the gas atmosphere at a temperature of 500° C. or higher for 15 minutes or longer. The sensor element includes an electrochemical pumping cell constituted of an oxygen-ion conductive solid electrolyte and an electrode having a NOx reduction ability. A NOx gas in a measurement gas is reduced or decomposed in the electrode. A NOx concentration in the measurement gas is obtained based on a current which flows in the electrochemical pumping cell at a time of the reduction or decomposition.

Abstract: A method for measuring and/or calibrating a gas sensor for determining oxygenic gas components in gas mixtures in exhaust gases of internal combustion engines. The gas sensor has one internal pump electrode IPE, one external pump electrode APE and one decomposition electrode NOE. The measurement and/or calibration may be carried out during the ongoing operation of the gas sensor by removing the gas component and/or oxygen from one of the chambers, by introducing oxygen in a controlled manner into one of the chambers with the aid of electrochemical pumping processes. The changes caused by the introduced oxygen are measured against an additional electrode and the gas sensor may be measured and/or calibrated using the measured values.

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 method of making a sub-miniature “micro-chip” oxygen sensor is provided where multiple sensor elements are applied to a dielectric ceramic substrate consisting of a heater pattern, followed by a dielectric layer. Intermeshing electrodes are then applied either over the heater pattern/dielectric layers or on the opposite side of the substrate. The space between the intermeshing electrodes is filled with an n-type or p-type high temperature semiconductor which is covered by a porous protection layer. After singulation (dicing), the sensor element is assembled having conductors applied to the contact pads on the element and is packaged in an assembly for introduction to the exhaust stream of a combustion process. A large step-wise change in the resistance of the element takes place as a result of changes in oxygen content in the exhaust whereby one can determine if the exhaust is rich or lean for use in an engine management or combustion management systems for emissions control.

Abstract: A NOx sensor includes a sensor element equipped with first and second pumping cells to define first and second measurement chambers. The first pumping cell exerts an oxygen pumping action against the first measurement chamber to adjust the oxygen concentration in the gas under measurement within the first measurement chamber to a given level. The second pumping cell exerts an oxygen pumping action against the second measurement chamber to produce a pumping cell current according to the NOx concentration in the gas under measurement. When the moisture content of the gas under measurement changes from 2 vol % to 8 vol %, the NOx sensor allows a variation of NOx concentration detection value based on the pumping cell current in such a manner that the NOx concentration detection value reaches a transient peak value of 20 ppm or smaller and converges to ±5 ppm of a reference value within 5 seconds.

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 sensor device for sensing at least a proportion of at least one gas component of a gas in a measurement gas space, in particular for detecting oxygen in an exhaust gas of a combustion machine, is proposed. The sensor device includes at least one sensor element. The sensor element includes at least one first electrode and at least one first reference electrode and at least one second reference electrode. The second reference electrode is connected to at least one reference gas channel. The first electrode is connected to the first reference electrode and the second reference electrode by at least one respective solid electrolyte. The sensor element has at least one diffusion element between the first reference electrode and the reference gas channel.

Abstract: Method for diagnosing a NOx readings recorder which acquires a NOx concentration in an exhaust gas tract of an internal combustion engine and comprises two measuring chambers (110, 120), wherein the exhaust gas to be measured is supplied to the first measuring chamber (110) and an oxygen concentration is set by means of a first oxygen ion pump current (IP1), wherein the second measuring chamber (120) is connected to said first measuring chamber (110) and wherein both measuring chambers are disposed in a solid electrolyte, the oxygen content in the second measuring chamber (120) is determined; the oxygen content is additionally determined by a separate device; the two values characterizing the oxygen concentration are compared and a defective sensor is then suggested if the oxygen concentration value determined in the second measuring chamber (120) deviates from the oxygen concentration value determined by the separate sensor device by a predeterminable magnitude.

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: A gas sensor control apparatus 5 is connected to a gas sensor (8) including cells (14, 24) each having a pair of electrodes provided on a solid electrolyte body (13, 23), and includes a sensor drive circuit (52). The gas sensor control apparatus (5) includes an instruction unit for outputting an instruction for setting the sensor drive circuit (52) to a deenergization state so as to stop the supply of electricity to the cells (14, 24) and an instruction for setting the sensor drive circuit (52) to an energization state so as to supply electricity to the cells (14, 24); a setting unit (55) for setting the sensor drive circuit (52) to the deenergization state or the energization state; and a wiring anomaly detection unit (58) for detecting a wiring anomaly of the sensor drive circuit (52) or the gas sensor (8).

Abstract: A lambda probe in which a measuring point for oxygen in a sensor is connected via a diffusion gap with a reaction chamber. The reaction chamber drives oxygen along the diffusion gap. A desired oxygen partial pressure is set in the reaction chamber. The pump current, which is proportional to the strength of the stream of oxygen driven along the diffusion gap, can be used as a measurement for the partial pressure of the residual oxygen in the exhaust gas during a normal operating phase. The lambda probe can be operated for test purposes intermittently in a high or low phase, in which the oxygen partial pressure in the reaction chamber is a minimum or maximum value. While changing between the operating phases, by comparing the pump currents with empirical values, conclusions with regard to the ability of the probe to function can be derived.

Abstract: There is provided a control apparatus for a gas sensor, which has a sensor element equipped with first and second oxygen pumping cells. The sensor control apparatus is configured to drive the first oxygen pumping cell to adjust the oxygen concentration of gas under measurement, drive the second oxygen pumping cell to produce a flow of electric current according to the amount of oxygen pumped out of the oxygen concentration adjusted gas by the second oxygen pumping cell, perform specific drive control to control the amount of oxygen pumped by the second oxygen pumping cell to a predetermined level after startup of the sensor element and before the application of the drive voltage between the electrodes of the second oxygen pumping cell.

Abstract: A method for sensing an air-fuel ratio of exhaust gasses from an engine of a vehicle using a sensor is provided. The method may comprise pumping a current in a pumping cell during; reducing said pumping during a set of operating conditions; and adjusting a fuel injection amount or an air amount into the engine to maintain a desired air-fuel ratio based on the sensor. In this way, a reference voltage can be driven by chemical reactions to equilibrate and provide an accurate indication of stoichiometry, similar to a HEGO sensor. Likewise, outside of stoichiometry, the reference voltage is controlled in a one-sided fashion via positive and negative pumping current at respective voltage limits to provide an indication of air-fuel ratio over a wide range.

Abstract: There is provided a gas sensor, which includes a sensor element extending axially of the gas sensor and having a gas sensing portion at a front end thereof and an electrode portion at a rear end thereof, a cylindrical metal shell retaining therein the sensor element with the gas sensing portion and the electrode portion protruding from front and rear ends of the metal shell, respectively, and having a flange portion and a rear end portion located on a rear side of the flange portion, a cylindrical protection cover having a front end fitted onto the rear end portion of the metal shell so as to cover the electrode portion and a weld joint through which the entire circumference of the front end of the protection cover is joined through the metal shell. The weld joint extends from an end face of the protection cover to the metal shell.

Abstract: A gas measuring system, having a measurement sensor (1) which records an exhaust gas from an internal combustion engine and has an outer electrode (6), which is exposed to the exhaust gas to be measured, a first measuring cell (4), a second measuring cell (8) that is connected to the first measuring cell (4), and in which a measuring electrode (10) is arranged, and a reference electrode (11) that is exposed to the ambient air. The measuring cells (4, 8) are located in a solid electrolyte (2), and all the electrodes (10, 11) are in contact with the solid electrolyte.

Abstract: A method is disclosed for operating an electrochemical gas sensor with a measuring electrode pair and a pumping electrode pair. The method includes obtaining a measurement of the interfering species at a location spatially adjacent to a measuring electrode of the measuring electrode pair; and adjusting one or more of an operation or an output processing of the electrochemical gas sensor based on the measurement of the interfering species. In this manner, the measurement of the interfering species may be used to adjust the removal rates of the interfering species and/or to adjust an offset of an analyte measurement to compensate for the presence of the interfering species.

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: A procedure to calculate the Lambda value with a wideband Lambda sensor of an internal combustion engine of a motor vehicle is thereby characterized, in that from the measured pumping electricity and the sensitivities of the wideband Lambda sensor as well as the gas concentration ratios, in the lean operation an oxygen concentration and in the rich operation an oxygen deficit are determined and from these respectively a conclusion is drawn about the Lambda value using the Pischinger Formula.

Abstract: A sensor supervision system for periodically providing a test to accesses the status of a gas detection sensor, such as a carbon monoxide (CO) sensor, is provided. To access the status of the CO sensor, a processor provides a voltage to the sensor supervision system, such that a voltage is applied to CO sensor, charging the CO sensor. The status of the CO sensor is accessed by determining the change in the voltage charge of the CO sensor between two sampling time points. If the first sample voltage is substantially equal to the second sample voltage, i.e., a substantially constant voltage, the carbon monoxide sensor fails the test. However, if there is an change is the voltage change between the first and second sampled time points, the CO sensor passes the test.

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 method of making a sub-miniature “micro-chip” oxygen sensor is provided where multiple sensor elements are applied to a dielectric ceramic substrate consisting of a heater pattern, followed by a dielectric layer. Intermeshing electrodes are then applied either over the heater pattern/dielectric layers or on the opposite side of the substrate. The space between the intermeshing electrodes is filled with an n-type or p-type high temperature semiconductor which is covered by a porous protection layer. After singulation (dicing), the sensor element is assembled having conductors applied to the contact pads on the element and is packaged in an assembly for introduction to the exhaust stream of a combustion process. A large step-wise change in the resistance of the element takes place as a result of changes in oxygen content in the exhaust whereby one can determine if the exhaust is rich or lean for use in an engine management or combustion management systems for emissions control.

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: Using a gas detection voltage Vs output from a terminal CU, a determination is made at to whether, after startup of an air-fuel ratio detection apparatus (1), a full-range air-fuel ratio sensor (10) has reached a semi-activated state in which a determination can be made as to whether the air-fuel ratio is on the rich or lean side based on a change in a gas detection signal Vic. After determining that the sensor has reached the semi-activated state, the signal Vic is compared with a threshold to determine whether the air-fuel ratio is on the rich or lean side. In the apparatus (1), the potential difference between an outer pump electrode of a pump cell (14) and a reference electrode of an oxygen concentration measurement cell (24) is obtained via a first differential amplification circuit (53) as the gas detection signal Vic, the signal Vic being highly responsive to a change in air-fuel ratio of exhaust gas.

Abstract: A first cell having an electrolyte and a pair of electrodes on the surface of the electrolyte with one of the electrodes facing a gas chamber causes, upon receipt of an applied voltage, a current to flow in accordance with the amount of oxygen discharge while discharging oxygen from the chamber. An open-circuit-induced fault is detected in accordance with a current flow change that is caused by the first cell when the voltage applied to the first cell reverts to a reference level after a temporary deviation from the reference level. A second cell generates a signal in accordance with the oxygen concentration in the measurement target gas chamber. An open-circuit-induced fault is detected in accordance with a signal change that is generated from the second cell when the voltage applied to the first cell reverts to a reference level after a temporary deviation from the reference level.

Abstract: A gas sensor element has a solid electrolyte body of oxygen ionic conductivity, a target gas electrode and a reference gas electrode formed on both surfaces of the solid electrolyte body, respectively, a porous diffusion resistance layer, and a catalyst support trap layer. The porous diffusion resistance layer covers the target gas electrode and through which target gases to be measured are passing. The catalyst support trap layer is formed on the outer surface of the porous diffusion resistance layer and supports noble metal catalyst. In the gas sensor element, the noble metal catalyst is made of platinum, rhodium, palladium supported in the catalyst support trap layer. In particular, an addition amount of palladium in the total amount of the noble metal catalyst is within a range of 2 to 65 wt %.

Abstract: In at least one embodiment, a method is described for measuring concentrations of gas moieties in a gas mixture. A mixed-potential gas sensor is exposed to a gas mixture in order to obtain a first and a second mixed-potential gas sensor output responses. The first output response and a second output response are deconvoluted to measure a first analyte gas concentration and a second analyte gas concentration. Some of the output responses may be used as inputs to a control system.

Abstract: A gas detection apparatus including a gas sensor element and a gas-sensor control circuit. The gas sensor element includes at least one sensor cell including a solid electrolyte member and a pair of electrodes, and external connection terminals electrically connected to the electrodes. The gas-sensor control circuit includes control terminals electrically connected to respective external connection terminals of the gas sensor element, an inspection current supply circuit for supplying an inspection current to an inspected terminal, which is a control terminal to be inspected for presence or absence of a short circuit to a predetermined potential, an inspection potential measurement circuit for measuring the potential of the inspected terminal, and an uninspected terminal impedance increasing circuit for increasing the impedance of the gas-sensor control circuit as viewed from an uninspected terminal, which is a control terminal other than the inspected terminal.

Abstract: A sensor element for the determination of the concentration of gas components in a gas mixture, particularly of the concentration of gas components in the exhaust of internal combustion engines, with two electrodes, that together with a solid electrolyte constitute a pumping cell, whose outer pumping electrode is exposed to the gas mixture by way of a porous protective layer, and with a reference electrode, which is disposed on the solid electrolyte and is exposed to a reference gas, and which with a solid electrolyte and a Nernst electrode constitutes a concentration or Nernst cell, is thereby characterized in that at least periodically the Nernst voltage between the outer pumping electrode and the Nernst electrode is tapped and analyzed.

Abstract: A gas concentration measuring apparatus for use in air-fuel ratio control of motor vehicle engines is provided which is designed to select or determine a correction factor for an output of an A/F sensor, as produced through a sensor control circuit, for compensating for errors in circuit characteristics of the A/F sensor and/or the sensor control circuit to ensure the accuracy of measurement in the apparatus.

Abstract: In a procedure to recognize the gas composition of a gas mixture, which consists of at least two gases of preferably different diffusion properties, delivered to a wideband lambda sensor, especially a gas mixture of an exhaust gas of an internal combustion engine of a motor vehicle, whereby the lambda sensor has a pumping cell with at least one gas measurement chamber, provision is made for the recognition of the gas composition of the gas mixture to result by means of modulation of the gas in the gas measurement chamber. Preferably the air number in the gas measurement chamber of the pumping cell is periodically altered, whereby the sensitivity of the lambda sensor to the gases, of which there are at least two, likewise periodically changes.

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: A gas sensor having a gas sensor element which includes: a reference electrode; a solid electrolyte layer having oxygen ion conductivity; a detection electrode; and an electrode-protecting layer covering the detection electrode. The electrode-protecting layer is a porous body carrying catalytic metal, and includes: a detection electrode side portion having a catalytic metal loading ratio of more than 0% by weight and not more than 0.005% by weight; and a surface side portion provided closer to the outer surface of the electrode-protecting layer than the detection electrode side portion, the surface side portion having a catalytic metal loading ratio of 0.01% by weight or more.

Abstract: A method of sensor conditioning is proposed for improving signal output stability and differentiation between responses to different gases such as exhaust from combustion processes. A square wave (or saw tooth) voltage pulses of opposite polarity and equivalent amplitude are applied between sensor electrodes. Pulses are separated by pauses, when charging power supply is disconnected from the sensor and sensor discharge is recorded. Useful information regarding concentration of analyzed gases can be extracted from two measurement methods.: 1. Measuring open circuit voltage decay during the pause immediately following voltage pulse. 2. Measuring the charging current during positive (negative) pulses and the discharging current during pauses following voltage pulses.

Abstract: A method of operating a gas sensor is disclosed, wherein the sensor includes a pumping electrode configuration and a measuring electrode configuration, and wherein the method includes operating the sensor in a first mode in which a first, lower pumping potential sufficient to electrochemically remove an interfering compound from the sensor without electrochemically removing the analyte from the sensor is applied across the pumping electrode configuration and a measuring potential sufficient to electrochemically remove the analyte from the sensor is applied across the measuring electrode configuration; and operating the sensor in a second mode in which a second, higher pumping potential sufficient to electrochemically remove the analyte from the sensor is applied to the pumping electrode configuration.

Abstract: A gas concentration measuring apparatus for use in air-fuel ratio control of motor vehicle engines is provided which is designed to determine the concentrations of oxygen at different resolutions within a wide and a narrow range using a first and a second sensor signal which are amplified by first and second operational amplifiers at different amplification factors. The apparatus samples values of the first sensor signal at different concentrations of oxygen to find an output characteristic error of the first operational amplifier and determines an actual concentration of oxygen to calculate an output characteristic error of the second operational amplifier using the one of the first operational amplifier and the actual concentration of oxygen. This permits values of the first and second sensor signals to be corrected so as to compensate for the output characteristics of the first and second operational amplifiers.

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: A method for sensing an air-fuel ratio of exhaust gasses from an engine of a vehicle using a sensor, the sensor having a pumping cell and a reference cell, the method comprising pumping a current in the pumping cell during at least a first set of operating conditions; reducing said pumping during at least a second set of operating conditions; providing a signal from the sensor during at least the first and second sets of operating conditions; and adjusting at least one of a fuel injection amount and an air amount into the engine to maintain a desired air-fuel ratio based on the signal during at least the first and second sets of operating conditions.

Abstract: The gas sensor control apparatus is for controlling a gas sensor including a sensor element having a solid electrolyte layer, and first and second electrodes located on opposite sides of the solid electrolyte layer, the first electrode serving as a gas detecting electrode, the second electrode serving as a reference electrode, the sensor element generating, as a sensor output, a current flowing between the first and second electrodes having a value depending on concentration of a specific gas component contained in a gas under measurement. The gas sensor control apparatus includes a determination function of determining whether or not it is time for the gas sensor to start operation, and a control function of forcibly supplying oxygen from a side of the second electrode to a side of the first electrode on a temporary basis when a determination result of the first function becomes affirmative.

Abstract: A lambda probe (1) is used with the measuring apparatus for monitoring residual oxygen in an exhaust gas, in which a measuring point for oxygen in a sensor (2) is connected via a diffusion gap (22) with a reaction chamber (24). During operation of the probe the reaction chamber drives a stream of oxygen IO2 along the diffusion gap by means of a controllably adjustable oxygen partial pressure pi. By means of an electro-chemical, oxygen ion pump driven by an electrical pump current Ip, an oxygen partial pressure pi predetermined as a desired value is set in the reaction chamber. In this arrangement the pump current, the strength of which is proportional to the strength of the stream of oxygen driven along the diffusion gap, can be used as a measurement parameter for the partial pressure pm of the residual oxygen in the exhaust gas or its concentration. The residual oxygen can be monitored during a normal operating phase, the phase N.

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

Abstract: In detecting a deterioration of an air-fuel ratio sensor, a sensor output change speed integrated value is calculated when an element temperature of a solid electrolyte is stabilized at a low temperature. Successively, a sensor output change speed integrated value is calculated when the solid electrolyte element is stabilized at a high temperature. Finally, a deviation between the change speed integrated values is calculated. By comparing the deviation amount with a predetermined determinant, presence or absence of the deterioration is determined.

Abstract: Electrode having high activity to oxygen gas and low activity to flammable gas is provided. An oxygen pump includes oxide-ion conductive solid electrolyte 2, electrode 8 which is an inactive electrode, and active electrode 10. Electrode 8 is an electrode that includes Ce0.8Sm0.2O2-?. Electrode 8 is disposed on the gas detection chamber 12 side of solid electrolyte 2. Active electrode 10 is disposed on the open space side of solid electrolyte 2. Gas detection chamber 12 is an enclosed space defined by solid electrolyte 2, insulation layers 6, and diffusion control layer 4.