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 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 multiple frequency method for the operation of a sensor to measure a parameter of interest using calibration information including the steps of exciting the sensor at a first frequency providing a first sensor response, exciting the sensor at a second frequency providing a second sensor response, using the second sensor response at the second frequency and the calibration information to produce a calculated concentration of the interfering parameters, using the first sensor response at the first frequency, the calculated concentration of the interfering parameters, and the calibration information to measure the parameter of interest.

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 gas sensing member has a unit structure and a porous protective layer disposed on the unit structure. The unit structure has a solid electrolyte body, a gas measurement electrode disposed on a surface of the body and exposed to a measured gas entering at a gas inlet, a reference gas electrode disposed on another surface of the body and exposed to a reference gas, and a heater disposed close to the body. The heater has a heater substrate and heating elements disposed in the heater substrate. The heating elements heat the body. The heater substrate has side corner areas placed on side corners of the unit structure and being adjacent to the heating elements. The protective layer is disposed on the gas inlet such that the side corner areas are not covered with the protective layer and are directly exposed to the measured gas.

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 gas sensor for sensing the gas concentration in a measured gas mixture, particularly of a nitrogen compound, having a solid electrolyte which connects a first and a second electrode in an ion-conducting manner, the first electrode having a high activity with respect to oxidation or reduction of the gas component that is to be sensed, and the second electrode having a slight activity in this regard. The influence on the activity with regard to oxidation or reduction of the gas component to be determined, due to free oxygen present in the measured gas mixture, is approximately equally strongly pronounced at both electrodes.

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 proton conductor has a porous sintered body made of tetravalent metallic oxide. Pyrophosphate as tetravalent metallic compound is formed on surfaces and porous walls of the body, and in the inside of each pore of the body. A method produces the proton conductor by immersing the porous sintered body made of tetravalent metallic oxide into liquid solvent containing phosphate, and heating the porous sintered body at 400° C. over 4 hours. A carbon quantity detecting sensor has the proton conductor, a pair of a measuring electrode and a reference electrode, and an electric power source for supplying a predetermined current or voltage to the electrode pair composed of the measuring and reference electrodes. The measuring electrode is formed on one surface of the proton conductor to face the measuring gas. The reference electrode is formed on the other surface of the proton conductor to be apart from the measuring gas.

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: A sensor (1) including a plate-shaped sensor element (21) extending in a front-rear direction and having at least 3 electrode terminals (25) provided on at least one side surface (24) of the sensor element at intervals in a lateral direction; a plurality of metallic terminal members (51a, 51b) connected to the electrode terminals (25) of the sensor element (21); and a separator (71) surrounding and insulating the plurality of metallic terminal members (51a, 51b). The metallic terminal members (51a, 51b) each has a crimp portion (57a, 57b) formed at a rear end thereof and a lead wire (61) is crimp-connected to the crimp portion (57a, 57b). The crimp portions (57a) located at opposite sides with respect to the lateral direction face the side surface (24) of the sensor element (21), whereas the crimp portion (57b) faces away from the side surface (24) of the sensor element (21).

Abstract: The present invention provides oxygen partial pressure control apparatuses that can control the partial pressure of oxygen in atmospheric gases in processing apparatuses or the like to within the range of 0.2 to 10?30 atm, while maintaining low material and operational cost conditions.

Abstract: A gas sensor control device is disclosed as including a sensor cell having a negative terminal, to which a current-voltage converter is connected, and a differential amplifier is connected to the current-voltage converter to provide a current measured result applied to a microcomputer. The current-voltage converter has an opposite-to-sensor terminal to which another differential amplifier is connected. A sensor-side terminal of the current-voltage converter and another differential amplifier is electrically connected to each other via an electric pathway having a sensor-current flow disabling pathway in which a switch circuit is provided. Closing the switch circuit allows a potential difference between both terminals of the current-voltage converter is zeroed. With the switch circuit closed, the microcomputer calculates an element current correcting value, while detecting an electromotive force of the sensor cell based on which a failure is determined.

Abstract: The gas sensor control apparatus develops a first voltage based on a first reference voltage at a negative terminal of a gas sensor device through a resistor and a second voltage based on a second reference voltage at a positive terminal of the gas sensor device. A controller samples through the resistor a sensor current, as created upon the development of the first and second voltage for measuring the concentration of gas. When the impedance of the gas sensor device is measured, the controller alternates the first voltage across the first reference voltage. The value (i.e., a zero-point) of the voltage applied to the gas sensor device when the sensor current is zero (i.e., 0 mA) depends upon the first and second reference voltages. The zero-point is corrected by regulating the second reference voltage to match an applying voltage characteristic to the gas sensor device correctly.

Abstract: An apparatus, system and method maximizes efficiency and accuracy of measuring an ion concentration of a measured fluid by varying a flow of ions within a measuring cell in accordance with an output signal of a sensor cell. The pump current through a pump cell is switched between a constant positive current and a constant negative current when upper and lower thresholds of the output signal are reached. The pulse width ratio of the square wave produced by the varying current is compared to a pulse width ratio function derived from a calibration procedure to determine the ion concentration of the measured fluid. In one embodiment, the functions of the pump cell and sensing cell are performed by a single electrochemical cell.

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 gas concentration measuring apparatus for use in air-fuel ratio control of automotive engines is designed to determine the concentration of oxygen within a wide and a narrow range using a sensor current flowing through a sensor element. The apparatus includes an amplifier circuit equipped with an operational amplifier and a plurality of amplifying resistors and a switch. The switch is responsive to a request signal to switch a relation in electrical connection between an operational amplifier and the amplifying resistors to distribute the amplifying resistors into an input resistor and a feedback resistor for the operational amplifier to change an amplification factor of the amplifier circuit. This results in a change in resolution of measurement of the concentration of oxygen, thereby ensuring enhanced accuracy in determining the concentration of oxygen in a selected one of the narrow and wide ranges.

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

Abstract: A single cell oxygen sensor apparatus and method are disclosed. An yttrium-based stabilized layer having electrical terminals connected to the yttrium-based stabilized layer can be provided on a substrate, wherein the yttrium-based stabilized layer is excitable by a constant current applied to the electrical terminals. A plurality of electrodes are located on a side of the yttrium-based stabilized layer and a plurality of heater elements located on said substrate opposite said yttrium-based stabilized layer. The heater elements can maintain the yttrium-based stabilized layer at a particular temperature. A cavity is formed and located between the yttrium-based stabilized layer and the heater elements. The partial pressure of oxygen can be measured by comparing the partial pressure of oxygen within the cavity with respect to the partial pressure of oxygen in the atmosphere external to the single cell oxygen sensor apparatus.

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 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: 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: Described herein are methods for diminishing or preventing in electrochemical operating systems the deposition of a metal oxide on an electrode surface. The metal oxide is formed by electrochemically assisted reduction of volatile metal oxides formed from a metallic component exposed to oxidative environments. In one example, described herein are methods for diminishing or preventing poisoning of a cathode by applying a negative protection potential to the metallic component. In another example, described herein are methods for diminishing or preventing the deposition of a metal oxide on a cathode surface by removing oxygen from the metallic component itself and thereby decreasing the amount of released volatile oxide from the metallic component by use of an auxiliary oxygen pump cell.

Abstract: An oxygen sensor is employed for determining whether the exhaust air-fuel ratio is rich or lean. A voltage is applied to the oxygen sensor at device impedance calculation intervals to calculate device impedance. After device impedance calculation, a reverse voltage is applied to the oxygen sensor with a view toward promptly negating the influence of voltage application on the sensor output. Subsequently, the sensor output of the oxygen sensor is sampled at sampling time intervals until it is concluded that the device impedance calculation period is over.

Abstract: A method of correcting an output of a NOx sensor including: a first step of obtaining a sensor-variation relational expression based on a relationship between an Ip2/Ip0 value and an output change percentage for a calibration sensor; a second step of obtaining, from the relational expression, an output change percentage ? that corresponds to an Ip2/Ip0 value of a subject NOx sensor; a third step of calculating a pressure correction coefficient ? based on the obtained ?; and a fourth step of performing output correction on the subject NOx sensor by calculating the pumping current Ip2(p0) under a reference pressure based on the pumping current Ip2(p) and a pressure p of the measurement gas which are detected upon measurement of the NOx concentration in the measurement gas.

Abstract: A sensor control device, and a gas sensor and sensor control device for applying a voltage to a sensor element of the gas sensor including an oxygen ion conductor and a pair of electrodes formed on the oxygen ion conductor of the gas sensor. The sensor control device includes a potential output terminal electrically connected to one of the pair of electrodes and a potential reference terminal electrically connected to the other of the pair of electrodes constituting the sensor element. The sensor control device applies a target voltage to the sensor element via the potential output terminal, corrected to take into account variation in the potential of the potential reference terminal.

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: To provide a malfunction diagnosing method and apparatus capable of reliably determining a malfunction even where the malfunction occurs in a common wire connecting a gas sensor and a control circuit for driving it. In a gas concentration measurement unit 1 having a sensor control circuit 50 which is connected to a sensor element 10 including an oxygen pump cell 14 and an oxygen concentration detection cell 24 and controls and drives this sensor element 10, a variation state of a terminal voltage at one connecting point (specifically, a Vs+ terminal) other than connecting points between electrodes facing a measurement chamber of each cell 14 and 24 and a common wire 24 is detected by a malfunction detection circuit 53 and an arithmetic processor 54. Based on this variation state of the terminal voltage, diagnosis of malfunction in the common wire 42 is executed. When the common wire 42 is broken, the terminal voltage at the Vs+ terminal varies with oscillations.

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 multilayered air-fuel ratio sensor consists of a plurality of substrate layers. At least one heterogeneous boundary layer is interposed between the plurality of substrate layers. The heterogeneous boundary layer has a thickness in a range of 10 to 100 ?m. The heterogeneous boundary layer absorbs thermal shocks or any other stresses acting on the substrate layers and stops the growth of cracks.

Abstract: A gas sensor apparatus 3 in an air-fuel ratio detection system 1 includes a gas sensor element 4 which outputs a detection signal corresponding to air-fuel ratio, and a gas sensor control circuit 2 which includes a detection section 20 for outputting a first output signal VIP1, a second output signal VIP2, and a third output signal VIP3 in accordance with the detection signal. This detection section 20 outputs the first output signal VIP1 which changes in accordance with the air-fuel ratio at least within a wide first air-fuel ratio zone, the second output signal VIP2 which changes in accordance with the air-fuel ratio within a narrow zone in the vicinity of the stoichiometric ratio, and the third output signal VIP3 which changes in accordance with the air-fuel ratio within a narrow zone in the lean region.

Abstract: A sensor element of a gas sensor, which is used for determining the concentration of ammonia and, optionally, at least one further component of a gas mixture, in particular in exhaust gases of combustion engines. The sensor element includes at least one first auxiliary electrode and at least one measuring electrode positioned downstream in the flow direction of the gas mixture, which are in direct contact with the gas mixture, a signal generated by the measuring electrode being used at least intermittently for determining the concentration of ammonia. A potential, at which ammonia contained in the gas mixture is oxidized, is applied at least intermittently to the first auxiliary electrode or the measuring electrode.

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: A method and a sensor element are provided for determining the concentration of an oxidizable gas in a gas mixture, e.g., in exhaust gases of internal combustion engines. Within the sensor element of a gas sensor, nitrogen oxides, hydrogen, and/or carbon monoxide contained in the gas mixture are at least partially removed in an initial step. In a further step, the concentration of the gas to be detected in the gas mixture freed of nitrogen oxides, carbon monoxide and/or hydrogen is ascertained.

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: The present invention relates to a NOx sensor and a calculating method of total NOx concentration using the same, and more particularly, to a NOx sensor which has improved sensitivity to NO and NO2 and simply calculates NO, NO2 and total NOx concentration, and a calculating method of total NOx concentration using the same. The NOx sensor of the present invention comprises an oxygen ion conductive solid electrolyte 10; an oxide sensing electrode 20 formed at the oxygen ion conductive solid electrolyte 10; a noble metal electrode 30; and a lead line 40 connected to each of the oxygen ion conductive solid electrolyte 10 or the oxide sensing electrode 20 or the noble metal electrode 30, wherein the oxygen ion conductive solid electrolyte 10 and the oxide sensing electrode 20 form at least two interfaces.

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

Abstract: An 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: The invention relates to a gas sensor, especially a lambda probe, for determining the oxygen concentration in the exhaust gas of an internal combustion engine that is operated with a fuel/air mixture. Said gas sensor comprises a pump cell arranged in or on a sensor element, said pump cell having a first electrode and a second electrode that are separated from the exhaust gas by at least one layer, and an electronic circuit for producing a voltage applied between the first electrode and the second electrode and for measuring and evaluating a pump current thereby produced in order to make it possible to draw conclusions therefrom on the composition of the fuel/air mixture. The invention is characterized in that an additional outer electrode is arranged on the sensor element. Said additional electrode is exposed to the exhaust gas and supplied with a negative current.

Abstract: The present invention relates a gas concentration detecting apparatus capable of appropriately making a decision on activation of each of a pump cell, a monitor cell and a sensor cell of its gas concentration sensor. In the apparatus, a control circuit outputs an oxygen concentration value on the basis of a current flowing when a voltage is applied to the pump cell and outputs an NOx concentration value on the basis of a current flowing at the voltage application to the sensor cell. Moreover, the control circuit separately makes a decision on activation of the pump cell and a decision on activation of the sensor cell in the middle of the activation of the sensor. Still moreover, the control circuit makes the decision on the activation of the sensor cell after the activation of the pump cell reaches completion.

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: 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 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: An oxygen sensor 10 includes an oxygen detection element 20, which assumes a hollow tubular shape extending along the axis. The oxygen detection element 20 has a closed tip end and an opened rear end. An internal electrode layer 23 is formed on an inner circumferential surface 22 of the oxygen detection element 20. The sensor 10 also has a terminal member 30 which is in contact with the internal electrode layer 23 and in electrical connection therewith. The terminal member 30 has press contact portions 34c and 34d which come into press contact with the inner circumferential surface 22 of the oxygen detection element 20 to hold the terminal member 30 in the oxygen detection element 20, and conduction portions 35b which come into press contact with the internal electrode layer 23 on the inner circumferential surface 22 of the oxygen detection element 20 and into electrical connection with the internal electrode layer 23.

Abstract: Disclosed is a sensor for measuring the concentration of a gas component in a gas mixture. Said sensor comprises a solid electrolyte and electrodes which are separated from each other by means of the solid electrolyte and of which an outer electrode is exposed to the gas mixture while an inner electrode is disposed in a hollow space that is separated from the gas mixture with the aid of a diffusion barrier. The inventive sensor is characterized in that an additional outer electrode is exposed to the exhaust gas, said additional outer electrode being impinged upon by a current whose sign is the opposite of the current by which the outer electrode is impinged upon.

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 mixed potential sensor device and methods for measuring total ammonia (NH3) concentration in a gas is provided. The gas is first partitioned into two streams directed into two sensing chambers. Each gas stream is conditioned by a specific catalyst system. In one chamber, in some instances at a temperature of at least about 600° C., the gas is treated such that almost all of the ammonia is converted to NOx, and a steady state equilibrium concentration of NO to NO2 is established. In the second chamber, the gas is treated with a catalyst at a lower temperature, preferably less than 450° C. such that most of the ammonia is converted to nitrogen (N2) and steam (H2O). Each gas is passed over a sensing electrode in a mixed potential sensor system that is sensitive to NOx. The difference in the readings of the two gas sensors can provide a measurement of total NH3 concentration in the exhaust gas. The catalyst system also functions to oxidize any unburned hydrocarbons such as CH4, CO, etc.