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

Abstract: An oxygen sensor as a gas sensor has a vent hole for taking an atmosphere into an outer sleeve in an outer sleeve cover for covering the outer sleeve from above and manufactured by rubber. A filter unit made by a tubular member enlarged in diameter on a predetermined boundary, a sheet-shaped filter having a water repellent property and an oil repellent property, and an O-ring is fitted and inserted into this vent hole. The upper end portion of a large diameter portion is folded by bending processing. Folding portion nips and supports the filter and the O-ring between the folding portion and a step portion formed between a large diameter portion and a small diameter portion. It is sufficient to set the size of a filter to same size as the vent hole. The filter can be attached to a predetermined position of the outer sleeve cover.

Abstract: A wide range oxygen sensor comprising a first oxygen pump cell, the first pump cell comprising: a first and a second electrode, with a first communication zone therebetween, the first electrode being exposed to exhaust gas, the second electrode being exposed to a heat source; and wherein at least one element of said first pump cell incorporates a gas-diffusion limiting characteristic; a second oxygen pump cell, operating at opposite polarity from said first oxygen pump cell, electrically isolated from said first oxygen pump cell, and disposed within a sensor substrate, the second cell comprising: a third and a fourth electrode, with a second communication zone therebetween, the third electrode being exposed to exhaust gas, the fourth electrode being exposed to a heat source; and wherein at least one element of said second pump cell incorporates a gas-diffusion limiting characteristic; at least one heating element for providing heat to said second electrode and said fourth electrode; and an electrical circuit

Abstract: A gas sensor has improved electrical properties. In the top view of the layer planes of the body of the sensor, printed circuit traces for electrodes are arranged outside of cavities in the body, e.g., outside of the reference air duct. Furthermore, the electrodes are enlarged in the direction of the exhaust-side end of the sensor. Also, the printed circuit traces have an increased layer thickness or are formed as a double layer.

Abstract: A gas sensing element comprises a solid electrolytic element, a measured gas sensing electrode provided on an outer surface of the solid electrolytic element, and a reference gas sensing electrode facing a reference gas chamber. A heater is accommodated in the reference gas chamber. A contact portion is provided on an outer cylindrical surface of the heater so that the contact portion is brought into contact with an inside surface of the solid electrolytic element defining the reference gas chamber. A heating peak position of the heater is in the vicinity of the contact portion.

Abstract: A gas concentration measuring apparatus for use in air-fuel ratio control of motor vehicle engines is provided which includes a laminated sensor element and a sensor circuit. The sensor circuit includes a current-measuring resistor, at least one amplifier, and A/D converters. The current-measuring resistor functions to measure a current signal flowing through the sensor element produced upon application of the voltage to the sensor element. The amplifier works to amplify the current signal to output it to one of the A/D converters to determine the concentration of the air-fuel ratio within one of a plurality of measurement ranges defined within the wide gas concentration measuring range. The amplification of the current signal results in expansion of the level of the input to the A/D converter, thus enhancing the resolution in determining the air-fuel ratio.

Abstract: The invention is directed to a circuit arrangement for operating an exhaust-gas probe including a NOx double chamber sensor. The exhaust-gas probe includes: a heatable solid-state electrolyte body having first and second pump chambers and diffusion barriers for separating the chambers from each other and from the exhaust gas. A third chamber communicates with the atmosphere. An external pump electrode is exposed to the exhaust gas and a first oxygen pump electrode is disposed in the first pump chamber. A second oxygen pump electrode is disposed in at least one of the first and second pump chambers and a nitrogen oxide pump electrode is disposed in the second pump chamber. An air reference electrode is disposed in the third chamber. Only one pump voltage generating circuit unit is provided and a switching device switches the pump voltage generating circuit unit between respective ones of the pump electrodes.

Abstract: A measuring arrangement for the analysis of gas components in gas mixtures, having at least one electrochemical solid electrolyte test cell with at least one cathode in a diffusion channel is exposed to a gas mixture. The use of several cathodes wired one behind the other makes possible selective analysis of individual gas components. At the first cathode, oxygen is selectively pumped off by the use of specifically oxygen-ion-conductive layers so that another component of the gas mixture can be analyzed by the following electrode.

Abstract: An electrochemical sensor for determining gas components and/or gas concentrations in gas mixtures using a sensor element is described; it has at least one electrode arranged on an ion-conducting solid electrolyte body bordering on a gas space in at least some areas. The electrode has at least two layers, the second layer which faces the gas space having a higher electron conductivity in comparison with the first layer which faces the solid electrolyte body.

Abstract: A measured gas side electrode is provided on one surface of a solid electrolytic substrate so as to be exposed to a measured gas. A reference gas side electrode is provided on an opposite surface of the solid electrolytic substrate so as to be exposed to a reference gas stored in a reference gas chamber. A water-vapor absorbing member is provided in the reference gas chamber.

Abstract: An electrochemical sensor element for determining the oxygen concentration in exhaust gases of internal combustion engines is described. The sensor element has a pump cell, which has a pump electrode situated on a surface of the sensor element facing the gas mixture, and a measuring gas electrode situated in a measuring gas area, the gas mixture entering the measuring gas area through a diffusion resistor. In addition, the sensor element has a reference electrode situated in a reference gas area. Another diffusion resistor is provided between the measuring gas area and the reference gas area.

Abstract: To provide a gas sensor and a method of sensing the gas concentrations which are capable of a battery drive through low power consumption and highly reliable, the gas sensor in which an electromotive force type gas sensor element is formed on a substrate, wherein the electromotive force type gas sensor element has a heating element formed on the substrate, a layer of solid electrolyte formed with an insulating layer interposed on the heating element and two electrodes formed on the solid electrolyte and is characterized in that the substrate is a heat-resistant glass base substrate.

Abstract: A NOx sensor for measuring NOx concentration including a main pumping cell and a detecting electrode, the main pumping cell-including an electrode having no decomposing/reducing ability for NOx or a low decomposing/reducing ability for NOx, to be used to control oxygen concentration in a measurement gas to have a predetermined value at which NO is not substantially decomposable, and the detecting electrode having a certain decomposing/reducing ability for NOx or a high decomposing/reducing ability for NOx, to be used so that NOx is decomposed to measure the NOx concentration by measuring an amount of oxygen produced during this process, wherein a cermet electrode composed of a Pt—Rh alloy and a ceramic component is used as the detecting electrode. Accordingly, it is possible to suppress the oxidation of Rh and the reconversion into the metal contained in the detecting electrode, stabilize the impedance, and stabilize the sensitivity to NOx.

Abstract: Disclosed herein is a method for producing a gas sensor, comprising disposing a reference electrode on a side of an electrolyte, disposing a measuring electrode on a side of the electrolyte opposite the reference electrode, disposing a first protective coating on a side of the measuring electrode opposite the electrolyte, treating the sensor with an aqueous salt solution comprising chloride and carbonate salts comprising elements selected from the group consisting of Group IA and IIA elements of the Periodic Table to form a treated sensor comprising the chloride and the carbonate salt mixture, drying the treated sensor, and disposing a second protective coating on a side of the first protective coating opposite the measuring electrode.

Abstract: A gas sensor is provided which comprises a sensor element for detecting a component of a gas and a cup-shaped protector for covering a detecting section of the sensor element. The protector is dual-walled and have cup-shaped inner and outer protector members. The inner and outer protector members are constructed and arranged so that g1>g2 where g1 is the distance between an inner surface of a circumferential wall of the outer protector member and an outer surface of a circumferential wall of the inner protector member and g2 is the distance between an inner surface of a bottom wall of the outer protector member and an outer surface of a bottom wall of the inner protector member. The outer protector member has at the circumferential wall thereof a plurality of first gas holes. The inner protector member has at the circumferential wall thereof a plurality of second gas holes.

Abstract: For the reduction of internal stresses and formation of cracks caused thereby, an exhaust gas probe includes two measuring electrodes separated by a solid electrolyte layer made substantially of ZrO2 and a circuit-board conductor layer for electrically heating the solid electrolyte layer. The circuit-board conductor layer is firmly connected to the solid electrolyte layer via a first sealingly sintered insulating layer made of an Al2O3-containing material. A pore-forming material is added to the Al2O3-containing material before. sintering.

Abstract: The present invention discloses a gas sensing device, an oxygen pumping cell, and a gas detection apparatus using the same for detecting lower ranges of gas concentration with high accuracy and stability. An under layer made of oxygen-ion-conductive solid electrolyte was formed between an electrolyte substrate and a sensing electrode, a conversion electrode or a gas treatment electrode. This allows the physical and chemical adhesion between these electrodes and the electrolyte substrate, thereby improving the sensing properties and stability.

Abstract: An improved structure of a mechanical seal for keeping a gas chamber and a reference gas chamber airtight in a sensor body. A sensor element is disposed within an insulator. A gap between the sensor element and the insulator is sealed hermetically by a glass sealing member. The glass sealing member has a coefficient of thermal expansion whose differences between itself and the sensor element and the insulator is within a range of ±3×10−6/° C. This provides a mechanical seal required to keep the reference gas chamber and the gas chamber in the gas sensor airtight in an environment such as an automotive exhaust system subjected to a great temperature change.

Abstract: In a gas sensor element having a measurement gas chamber for introducing a measurement gas thereinto, a sensor cell, and an electrochemical cell, the sensor cell has an active electrode facing the measurement gas chamber, a first reference electrode forming a pair with the active electrode, and a solid-electrolyte plate having both the electrodes, and is so constructed that the concentration of a specific gas in the measurement gas chamber is detectable. The electrochemical cell has an inactive electrode facing the measurement gas chamber and being inactive to the specific gas, a second reference electrode forming a pair with the inactive electrode, and a solid-electrolyte plate having both the electrodes. The inactive electrode is formed of a metallic material containing at least one selected from Au, Ag, Cu and Pb and an additional metallic material Rh. This gas sensor element promises good measurement precision.

Abstract: An electrochemical sensor element, in particular for determining the oxygen level in gas mixtures, includes at least one measuring electrode exposed to a measured gas, at least one reference electrode exposed to a reference gas, at least one heating device, and one reference gas channel, through which the reference gas can be supplied to the reference electrode. The reference electrode is connected to the reference gas via a volume provided with pores. The volume is formed in a layer between the reference gas channel and the reference electrode.

Abstract: A sensor structure having a metallic terminal member. The metallic terminal member 23 includes press portions 23d and 23e, which press the heating member 3 in a direction intersecting the center axis of a hollow portion 2a of an oxygen detection element 2. Holding means for holding the heating member 3 is formed separately from the metallic terminal member 23. Thus, without use of special heating-member holder means, the metallic terminal member 23 can bring at least a portion of the heating member 3 into contact with the inner wall surface of the hollow portion 2a of the oxygen detection element 2.

Abstract: An oxygen sensor element is provided which may be used in an oxygen sensor designed to measure the concentration of oxygen contained in exhaust gasses of an automotive internal combustion engine. The gas sensor element includes a solid electrolyte body, a target gas electrode, a reference gas electrode, and a catalytic layer formed over the target gas electrode. The catalytic layer is made of heat resisting ceramic grains which hold thereon catalytic metal grains whose average grain size is 0.3 to 2.0 &mgr;m, a weight of catalytic metal grains per unit area of the catalytic layer, as defined by projecting the target gas electrode on a plane, is 10 to 200 &mgr;g/cm2. This facilitates the reaction of exhaust gasses such as H2, NOx, and HC with O2 over the target gas electrode, thus resulting in improved accuracy of a sensor output over a wide temperature range.

Abstract: An electrochemical sensor has a sensor element, and is used to determine a gas concentration of a gas to be analyzed. The sensor element has a first solid electrolyte layer, an electrode that includes an electrode surface and an electrode lead, and a second solid electrolyte layer; a gas channel being introduced into the first solid electrolyte layer in such a manner, that the electrode is situated in a first, clamped region between the first and the second solid electrolyte layers, and in a second, open region between the second solid electrolyte layer and the gas compartment. In a transition region between the clamped region and the open region, the electrode borders on a layer pattern, which is constructed in such a manner, that the electrode is subjected to a lower pressure during a laminating procedure.

Abstract: A gas concentration measuring apparatus is provided which includes a gas concentration sensor consisting of a pump cell, a sensor cell, and a monitor cell. The pump cell works to determine the concentration of O2. The sensor cell works to decompose an oxygen containing gas such as NOx and provide an output indicative of the concentration of NOx. The apparatus also includes an applying voltage determining circuit which looks up a predetermined voltage-to-current relation to determine a target voltage to be applied to the pump cell as a function of the current produced by the pump cell so as to preclude the pump cell from decomposing the oxygen containing gas component, thereby minimizing an error in determining the concentration of oxygen containing gas as a function of the output of the sensor cell.

Abstract: An electrochemical gas sensor for determining the concentration of gas components in a gas mixture, in particular for determining NOx and HC. The gas sensor includes a first measuring gas space which is connected to the measuring gas, and a second measuring gas space which is connected to the first measuring gas space by a connecting channel. Furthermore, a first electrode and a second electrode, arranged in the first measuring gas space, and at least one third electrode arranged in the second measuring gas space, and at least one fourth electrode are provided. The two measuring gas spaces are arranged in layer planes on top of one another and are separated from one another by at least one oxygen ion conducting layer, the connecting channel passing through the oxygen ion conducting layer.

Abstract: The NOx concentration in a gas is determined with a thick-film measuring sensor which has two measuring cells. The raw measured value of the measuring sensor is corrected by a multiplicative correction value and an additive correction value, which are both taken from a characteristic map. The characteristic map depends on the oxygen-ion pumping current in the second measuring cell, the measured gas temperature, and the measuring sensor temperature.

Abstract: A sensor element, having a ceramic body made of a laminate having at least one ceramic foil and having a heating element embedded in the ceramic body. At least the longitudinal edges of the ceramic body have a chamfer. The heat source formed by the heating element lies in the direction of the bisector of an angle which is enclosed by a chamfer's edge lying closest to the heating element. The chamfer is formed in such a way that the angle enclosed by the large surface side edge, is larger than an angle enclosed by a narrow side edge.

Abstract: A hydrogen sensor and process for measuring hydrogen gas concentrations includes a pump cell and a measuring cell. The pump cell includes a first conducting electrolyte layer having a top and a bottom surface, and an electrode disposed on the top and bottom surfaces, wherein the top electrode is in communication with an unknown concentration of hydrogen gas. The measuring cell includes a second conducting electrolyte layer having a top and a bottom surface, and an electrode disposed on the top and bottom surfaces, wherein the bottom electrode is in communication with a reference gas source. A diffusion-limiting barrier is disposed between the pump cell bottom electrode and the measuring cell top electrode, wherein hydrogen diffusion through the diffusion-limiting barrier is controlled by a Knudsen diffusion mechanism at hydrogen concentrations greater than about 40%.

Abstract: The poison resistant sensor comprises a sensing electrode (4) having a first and second side; a reference electrode (7) having a first and second side; an electrolyte (1) disposed between and in intimate contact with the first side of the sensing electrode and the first side of the reference electrode; a first side of a protective layer (3) disposed adjacent to the second side of the sensing electrode; and a protective coating (17), comprising alpha alumina and gamma alumina, disposed in physical contact with the second side of the protective layer.

Abstract: An electrochemical measuring sensor for determining gas components and/or gas concentrations in gas mixtures, having a sensor element which has at least one signal-forming electrode having a supply lead of the signal-forming electrode and at least one electrical element whose electrical potential differs from the electrical potential of the supply lead of the signal-forming electrode. The supply lead of the signal-forming electrode is at least regionally surrounded by an electrically conducting shielding, so that fault currents appearing because of the potential difference between the supply lead of the signal-forming electrode and the electrical element flow at least predominantly between the electrical element and the shielding.

Abstract: An improved structure of a mechanical seal for keeping a gas chamber and a reference gas chamber airtight in a sensor body. A packing seal is disposed between a shoulder formed on an inner wall of a housing of the sensor body and a tapered surface of an insulation porcelain installed in the housing to define the gas chamber and the reference gas chamber hermetically. The packing ring is formed by a metal plate which has a thickness of 0.1 mm or more and a Vickers hardness of 200 or less and which is made of at least one of a nickel, a nickel alloy, a titanium, and a stainless steel.

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

Abstract: A gas sensor element is provided which is used in a gas sensor such as an oxygen sensor. The gas sensor element includes a solid electrolyte body, a target gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a gas to be measured, and a reference gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a reference gas. Each of the target gas electrode and the reference gas electrode is made up of a plurality of crystal grains defined by grain boundaries. The total length of the grain boundaries in each of the target gas electrode and the reference gas electrode is 1000 &mgr;m or more in a surface area of 1000 &mgr;m2. This ensures a sufficient degree of diffusion of the gasses in the target and reference gas electrodes, thereby providing a rapid response rate to the gas sensor element.

Abstract: In a planar sensor element having a gas-containing layer situated between impermeable covering layers, the gas-containing layer is enclosed by a sealing frame over its entire periphery in a plane running between the covering layers, and at least one of the covering layers has a through hole for the exchange of air (reference gas) between the gas-containing layer and the ambient environment.

Abstract: An electrochemical sensor for ascertaining gas concentrations in gases, particularly in exhaust gases of combustion engines, includes an oxygen-ion-conductive solid electrolyte which is provided with electrode layers arranged at a distance from one another and with at least one resistance heating element that is separated from the solid electrolyte by an electrical insulating layer, a foil binder layer being provided between the electrical insulating layer and the solid electrolyte. At least one electron-conductive intermediate layer is provided between the electrode-side electrical insulating layer and the adjacent solid electrolyte.

Abstract: A moisture sensor working to measure a moisture content of a specified measurement gas is provided which consists of an electrochemical cell having a first electrode exposed to the measurement gas and a second electrode exposed to a reference gas and a controller. The electrochemical cell outputs an electrical energy arising from chemical reaction of the measurement gas with the reference gas. The controller controls at least one of voltage appearing across and current flowing through the electrochemical cell and uses one of them to measure the moisture content of the measurement gas. This enables the moisture content to be determined free from the humidify of the measurement gas.

Abstract: A flat limiting-current sensor 10 includes a solid electrolyte substrate 22, a negative electrode 34a and a positive electrode 32a. The negative and positive electrodes 34a and 32a, respectively, are disposed on the same side of the solid electrolyte substrate 22. A voltage of 0.8 V is applied between the negative electrode 34a and the positive electrode 32a in order to determine oxygen concentration. The ratio between the area of the negative electrode 34a and the area of the positive electrode 32a is set to 1:2, thereby reducing element resistance to 74% that of the case where the negative electrode and the positive electrode assume the same area. Thus, the measurement accuracy of the flat limiting-current sensor 10 is improved.

Abstract: An electrochemical sensor element is described, in particular for determining the oxygen level in gas mixtures, having at least one measuring electrode (15) exposed to a measured gas, at least one reference electrode (17) exposed to a reference gas, at least one heating device (23), and one reference gas channel (21), through which the reference gas can be supplied to the reference electrode (17). The reference electrode (17) is connected to the reference gas via a volume provided with pores. The volume is formed in a layer between the reference gas channel (21) and the reference electrode (17).

Abstract: An objective gas to be measured is introduced into first and second chambers which are connected via a diffusion resistive passage. A first electrochemical cell is provided in the first chamber for pumping in and out oxygen in accordance with an applied voltage. A second electrochemical cell is provided in the second chamber and responsive to application of a predetermined voltage for generating a sensor current representing a specific gas concentration in the objective gas. The first electrochemical cell is located between the first chamber and a reference gas chamber so that oxygen pumping in and out operation can be performed between the first chamber and the reference gas chamber.

Abstract: Disclosed herein is a gas sensor having a small amount of lead oxide incorporated into an inner electrode and an outer electrode, and a method for depositing the lead oxide. The lead oxide is applied in an amount sufficient to effectuate consistent performance during sensor break-in. Lead oxide is transferred to the electrodes of the sensor element during the fabrication process by exposing the sensor element to glass having a known lead content during a heating step. Lead oxide from the glass is vaporized and deposited on the electrodes in the form of lead oxide. The deposited lead oxide is incorporated into the electrodes of the sensor element. The lead oxide reduces performance irregularities thereby improving performance during the initial use of the gas sensor.

Abstract: A gas sensor, comprising an oxygen pump cell with a first pump electrode and a second pump electrode disposed on opposite sides of a first solid electrolyte layer and a second pump electrode. The sensor also comprises an emf cell with an emf electrode and a reference gas electrode disposed on opposite sides of a second solid electrolyte layer. The emf electrode is disposed in fluid communication to the second pump electrode. A via hole is disposed through the first solid electrolyte layer, such that the first pump electrode is in fluid communication with the second pump electrode. A protective insulating layer, having a passage for gas to be sensed, is disposed in contact with the first pump electrode. A first insulating layer, having a conduit, is disposed in contact with the emf electrode. A second insulating layer, having an air channel, is disposed in contact with the reference gas electrode. A heater is disposed in thermal communication with the emf cell.

Abstract: A gas sensor is disclosed comprising an oxygen pump cell having at least one exterior pump electrode and at least one interior pump electrode disposed on opposite sides of a first solid electrolyte layer. An emf cell having a first and second emf electrodes and first and second reference gas electrodes are disposed on opposite sides of a second solid electrolyte layer. At least one insulating layer is in contact with the first and second emf electrodes. At least one via hole is disposed through the first solid electrolyte layer. At least one air channel is disposed through at least one insulating layer. An air vent is disposed in at least one insulating layer in contact with the first and second reference gas electrodes. A heater is disposed in thermal communication with the sensor. And at least five electrical leads are in electrical communication with said sensor. A method of using a gas sensor is also disclosed.

Abstract: A gas-sensing device is cooled down from 1470° C. to 457° C. after calcination when manufactured. The device comprises a solid electrolyte plate made of partially stabilized zirconia, a measurement electrode disposed on the plate to face an atmosphere of a gas to be measured, and a reference electrode disposed on the plate to face an atmosphere of a reference gas. A gas-permeable diffusion layer is laminated on the plate to cover the measurement electrode. A gas-non-permeable shield layer is laminated on the diffusion layer. A reference-gas-chamber forming plate is laminated on the solid electrolyte plate to form a reference gas chamber. One or more of the shield layer, diffusion layer, and reference-gas-chamber forming plate are made of a material that differs in a contraction percentage from the solid electrolyte plate by an amount of 0.3% or less.

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

Abstract: A method of adjusting an output of a gas sensor element is provided. The gas sensor element includes a lamination of a solid electrolyte body, a target gas-exposed electrode, a reference gas-exposed electrode, and a diffused resistance layer in which a target gas to be measured diffuses. The target gas-exposed electrode is disposed on a first surface of the solid electrolyte body exposed to the target gas. The reference gas-exposed electrode is disposed on a second surface of the solid electrolyte body exposed to a reference gas. The diffused resistance layer is disposed on the first surface of the solid electrolyte body. The target gas-exposed electrode and the reference gas-exposed electrode produce a sensor output. The adjustment of the sensor output is achieved by decreasing a diffusion length of the target gas in the diffused resistance layer as a function of a quantity of the sensor output to be adjusted by, for example, removing a portion of the diffused resistance layer.

Abstract: An exhaust gas sensor element has an electrolyte body, an inner electrode disposed on an inner surface of the electrolyte body, an outer electrode disposed on an outer surface of the electrolyte body, and a ground isolating coating disposed over the outer electrode. The ground isolating coating is typically alumina and extends from an active end of the electrolyte body toward an opposing end of the electrolyte body. The invention also includes a method for constructing a gas sensor element, the steps of which comprise forming an electrolyte body having an inner surface and an outer surface, applying an electrode ink to the inner surface to form an inner electrode and to the outer surface to form an outer electrode, and depositing a combination poison resistant/ground isolating coating, which is typically alumina, over the outer surface such that the combination coating extends from an active end of the electrolyte body toward an opposing end of the electrolyte body.

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

Abstract: A gas sensor element is provided which is used in a gas sensor such as an oxygen sensor. The gas sensor element includes a solid electrolyte body, a target gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a gas to be measured, and a reference gas electrode provided on a surface of the solid electrolyte body so as to be exposed to a reference gas. Each of the target gas electrode and the reference gas electrode is made up of a plurality of crystal grains defined by grain boundaries. The total length of the grain boundaries in each of the target gas electrode and the reference gas electrode is 1000 &mgr;m or more in a surface area of 1000 &mgr;m2. This ensures a sufficient degree of diffusion of the gasses in the target and reference gas electrodes, thereby providing a rapid response rate to the gas sensor element.

Abstract: A circuit configuration for generating a virtual ground includes a micro-controller, an analog circuit and a read-only memory. A pulse-width modulated signal, which is output by the micro-controller, is converted, by using the analog circuit, into the virtual ground as a common reference potential of an exhaust probe which operates according to the principle of the galvanic oxygen concentration cell with a solid electrolyte. The actual value of the virtual ground is read into the micro-controller through the use of an A/D converter and is compared with a predefined setpoint value. The potential value of the virtual ground is then controlled on the basis of the difference value. An exhaust probe configuration is also provided.

Abstract: An objective gas is successively introduced into first and second chambers which are connected via a narrow passage. A first monitor cell, provided on a surface of the first chamber, generates an electromotive force representing an oxygen concentration in the first chamber. A second monitor cell, provided on a surface of the second chamber, generates an electromotive force representing an oxygen concentration in the second chamber. A voltage applied to a pump cell is controlled based on the electromotive forces obtained from the first and second monitor cells.