Abstract: Apparatus and method for detecting and measuring hydrogen and gaseous compounds capable of dissociating into or combining with hydrogen ions using a solid electrolyte concentration cell. A novel solid electrolyte membrane is used which comprises an organic polymer-inorganic compound blend prepared by admixing an organic polymer such as poly(vinyl alcohol) with a heteropoly acid or salt thereof such as dodecamolybdophosphoric acid in a mutually miscible solvent.

Abstract: An oxygen sensor comprising an oxygen sensing unit sensitive to oxygen in an oxygen-containing gas and operative to produce an electric signal variable with the concentration of oxygen in the oxygen-containing gas when contacted by a stream of the gas, and a dual-shell housing structure comprising an outer shell and an inner shell enclosed within the outer shell and spaced apart inwardly from the outer shell to form a first chamber therebetween, the inner shell having defined therein a second chamber having the oxygen sensing unit fixedly held in position therewithin, the outer shell being formed with at least one port open to the first chamber and the inner shell being formed with at least one port open to the first and second chambers, the port in one of the outer and inner shells being out of alignment with the port in the other shell in a direction substantially perpendicular to the longitudinal measurement of the sensing unit and passing through a predetermined point of the sensing unit.

Abstract: An electrochemical device comprising at least one electrochemical cell having a planar solid electrolyte body, and a first and a second electrode one of which is disposed on the solid electrolyte body. The device has a measurement-gas space communicating with an outside space for introducing a measurement gas, and a reference-gas space into which a reference gas is introduced. The first and second electrodes are exposed to the measurement-gas and reference-gas spaces, respectively. The measurement gas is introduced into the measurement-gas space with a diffusion resistance to molecules of a selected component of the measurement gas. The measurement-gas and reference-gas spaces are juxtaposed in spaced-apart relation with each other in substantially the same plane parallel to the planar solid electrolyte body.

Abstract: An electric connection terminal arranged at a rear end of a sensor element and capable of affording quick and easy connection of the sensor element with a contacting element connected to a lead wire extending into a connector socket or connector insulator accommodating the contacting element for transmitting a signal detected at the front end of the sensor element, is composed of at least two conductive layers, and at least the lowermost layer of the conductive layers is composed of a mixture of a conductive metal and ceramics and/or glass, so that the layers bond firmly with each other and the lowermost layer bonds most firmly to the sensor element, whereby peeling-off of the connection terminal from the sensor element due to friction thereof against the contacting element and repetition of heating and cooling of the sensor element is eliminated.

Abstract: Apparatus and method for detecting and measuring hydrogen and gaseous compounds capable of dissociating into or combining with hydrogen ions using a solid electrolyte concentration cell. A novel proton-conducting membrane comprised of an interpenetrating polymer network serves as the solid electrolyte. A reference gas or a solid reference substance is used. For increased strength, a membrane may be composited with or utilized with a porous support.

Abstract: A modified zirconia oxygen sensor is disclosed wherein gas flows through inner (14) and outer tubes (12) and wherein one electrode (18) is attached to the inner surface of the inner tube (14), and the second electrode (16) is attached to the outer surface of the inner tube (14). The outer catalytic surface of inner tube (14) is made inert so that an oxygen potential difference is produced between the electrodes (16, 18) which results in a voltage output, as read by the oxygen analyzer (42), which is proportional to the initial level of the combustible in the gas. The utilization of inner (14) and outer tubes (12) wherein the portion of the gas sample contacting the active electrode (18) is maintained separate from the portion of the gas sample contacting the inactive electrode (16) prevents back or edge diffusion between the electrodes.

Abstract: Apparatus and method for detecting and measuring hydrogen and gaseous compounds capable of dissociating into or combining with hydrogen ions using a solid electrolyte concentration cell. A novel solid electrolyte membrane is used which comprises a three-component blend prepared by admixing an organic polymer or copolymer, such as poly(vinyl alcohol), with an inorganic compound, such as a phosphoric acid, and an organic compound selected from a group of polymers and copolymers having monomer units containing nitrogen, oxygen, or sulfur atoms, such as poly(vinyl pyrrolidone), in a mutually miscible solvent. A reference gas or a solid reference substance is used. For increased strength, a membrane may be composited with or attached to a porous support.

Abstract: A novel electrochemical cell including a solid electrolyte heated to an elevated temperature for operation and an integral cell electrode/heater for heating the electrolyte. Solid electrolyte embodiments are described. The integral electrode/heater is applied to a surface of the solid electrolyte and is resistively heated by an alternating electric current. A portion of the solid electrolyte may also be resistively heated. The described or comparable cells may be incorporated into an oxygen detector or similar apparatus where the apparatus is operated by alternately heating the cell and measuring the emf developed by the cell across its electrode.The invention is also, in part, a unique, solid electrolyte-integral cell electrode/heater configuration which provides a zone of uniform maximum heating at a predetermined location within the electrolyte and which, when used with a suitable resistive heating electric current, confines the current to the integral electrode/heater prolonging cell life.

Abstract: A solid state electrochemical ceramic cell adapted to alter the composition of gas exhaust streams containing noxious component passing therethrough comprising: a porous, high surface area body having a gas-receiving first end seal portion, a gas egressing second end seal portion and substantially gas impervious side walls defining the length of the cell; a high surface area, porous solid electrolyte forming the body of the cell interior; a gas communicating passageway through the cell length extending from the first seal end portion through the second seal end portion and adapted to carry gas through the length of the cell; a first electronically conductive region and a second electronically conductive region, said regions disposed in electronically opposing segment of the cell; a first electrode connection member located in said first conductive region and a second opposing electrode connection member located within said second conductive region; said end seal portions adapted to be positioned in gas-tight

Abstract: Apparatus for sensing oxygen concentration using a solid electrolyte of cylindrical shape, with a heater disposed within the solid electrolyte, is disclosed. The member supporting the heater, and the leads for the heater, are integrally bonded to the heater through an inorganic bonding member such as glass. By integrally bonding the support member and leads through an inorganic bonding member, the heater length can be reduced.

Abstract: A measuring electrode is mounted on one side surface of a solid electrolyte, while a reference electrode is mounted on a separate solid electrolyte and disposed so as to face the opposite side surface of said one solid electrolyte across a gap.

Abstract: An electrochemical device comprising at least one electrochemical cell having a planar solid electrolyte body, and a first and a second electrode one of which is disposed on the solid electrolyte body. The device has a measurement-gas space communicating with an outside space for introducing a measurement gas, and a reference-gas space into which a reference gas is introduced. The first and second electrodes are exposed to the measurement-gas and reference-gas spaces, respectively. The measurement gas is introduced into the measurement-gas space with a diffusion resistance to molecules of a selected component of the measurement gas. The measurement-gas and reference-gas spaces are juxtaposed in spaced-apart relation with each other in substantially the same plane parallel to the planar solid electrolyte body.

Abstract: To provide an easily manufactured and easily connected heater element for a tubular ion-conductive body (26) forming a sensing element (24) of the oxygen sensor, the heater element (35) comprises a plate-like substrate (36) of insulating material, e.g. ceramic, which, at its inner end is wider than at the end fitting into the inside of the tubular ion-conductive body, the conductors leading to the heater being formed as conductive tracks spaced apart from each other by a greater distance at the inner end, adjacent connection zones (37/3), than close to the heater zone (37/1), the plate-like substrate, at the inner portion, being essentially trapezoidal and terminating in an end edge (36') which forms the wider side of the trapezoid.

Abstract: An air-fuel ratio detector including an oxygen ion conductive solid electrolyte, first and second electrodes provided on respective sides of the solid electrolyte, a porous diffusion resistor covering the first electrode, and a circuit arrangement for supplying a current between the first and second electrodes. In order to enable a detection of a wide range of air-fuel ratios, the current supplied between the first and second electrodes is controlled so as to feed oxygen from the second electrode to the first electrode through the solid electrolyte and then withdraw oxygen from the first electrode to the second electrode through the solid electrolyte.

Abstract: The oxygen sensor has a solid electrolytic element made of an oxygen ion-conducting metal oxide. This element is formed in a cup shape, closed at one end and opened at its other end. The outer peripheral surface of the element is exposed to exhaust gas, and the inner peripheral surface of the element is exposed to the atmosphere. A first electrode is fixed to the outer peripheral surface of the element, and a second electrode is fixed to the inner peripheral surface of the element. An electrically insulating layer is formed on the outer peripheral surface of the element except where the first electrode is disposed. A metal lead of thin film, connected to the first electrode, is formed on the insulating layer. Further, a retaining lead connected to the first electrode is formed on the metal lead. This retaining lead is formed by densely sintering a conductive material and a binding material.

Abstract: An engine air/fuel ratio sensing device for measuring the oxygen partial pressure or concentration in the exhaust gas of an engine. The device has a sensor and a control circuit coupled to each other. The sensor consists of an electrolyte oxygen pump cell and an electrolyte oxygen sensor cell, both cells having a gap portion therebetween. The oxygen pump cell pumps oxygen into ambient gas when electrically energized. The sensor cell produces an electromotive force when there is an oxygen partial pressure difference thereacross due to the pumping of the pump cell. The control circuit has a differential amplifier which receives as an input the electromotive force for comparison with a predetermined reference voltage. The amplifier continuously provides an output, used for driving a pumping current through the pump cell, until the electromotive force reaches the reference voltage at which an equilibrium condition for the pumping current is established.

Abstract: A rodlike ceramic member of a heater projects towards and into the active tip of the solid electrolyte tube of an oxygen sensor, extending out from the bottom end of the principal insulating member of the sensor which is made of the same ceramic material. Conducting paths of the heater are brought up to a shoulder where the wider insulating part joins with the carrier of the heater, for connection with conductors leading to the end of the main insulator which is remote from the measuring gas and, furthermore, on this shoulder, connections are also made between conducting paths of the solid electrolyte sensor probe and conductors leading to the end of the main insulator remote from the measuring gas. At that end of the main insulator, sleeve connections are made to connection wires for external connections.

Abstract: An oxygen probe for measuring the carbon potential of endothermic gas in a heat treating furnace. The probe uses a readily available, automative-type oxygen sensor having a solid electrolyte element. The sensor is mounted on a heat conducting base plate. The sensor element is surrounded by a gas flow tube extending from the base plate. Exit ports around the base of the sensor element extend through the base plate and into the area defined by the gas flow tube causing an axial, radially symmetric flow of gas around the sensor element. The tip of the element is heated above the temperature of the gas while the base of the element is conductively cooled by the base plate. A temperature gradient is thus caused along the length of the sensor element, increasing its sensitivity.

Abstract: The connection conductor leading from the connection end of a sensor element towards the end of the sensor remote from the gas to be measured is a metallic connection part (17) that is rigid against torsion and passes through the aperture (16) of the closure shell (14) where it is sealed by a bead-like element (41) having a tubular extension (48), beyond which the connection conductor has an axial internal connection surface for a cable (19). A sleeve (51) of yielding material (51) covers the adjoining ends of the cable and of the connecting conductor and an overlay shell (52) compresses the sleeve to make a tight seal, both around the cable and against the tubular end of the bead (41). The overlay shell snaps on to the tubular extension of the bead by interlocking annular sawtooth ridges.

Abstract: The probe comprises an outer casing communicating through apertures with the atmosphere of a furnace and bearing a support part on which the measuring electrode, or anode, is wound. A tablet of solid electrolyte in contact with the anode can be easily and quickly replaced when the measuring face thereof has become contaminated by the furnace atmosphere. The reference electrode, or cathode, is formed by the soldered junction and one of the wires of a thermocouple, the two conductors of which are crumpled into a hollow in the reference face of the tablet, then pass through a conduit of insulating refractory material. Between the bottom of the casing and that of a tubular support accommodated therein there is a spring which has the effect of pressing the tablet against a washer via the supporting part, thus sealing the furnace atmosphere from a reference atmosphere.

Abstract: An A/F (Air Fuel) ratio detector providing precise control of the operating A/F ratio of an internal combustion engine whether the engine is operating in the fuel-rich or fuel-lean region or at the theoretical (stoichiometric) point. The detector includes both a pump element and a sensor element, each composed of an oxygen-ion-conductive solid electrolyte having formed on both sides thereof a porous electrode. The pump and sensor elements are disposed facing one another with a small gap therebetween. A wall is disposed parallel to the sensor element on the side opposite the gap and is sealed to the solid electrolyte of the sensor element except at a base portion, thereby defining an air compartment open to the atmosphere. An electric current is passed through the pump element, and the resulting potential produced across the sensor element is taken as an indication of the operating A/F ratio.

Abstract: Zirconia powder is formed by dry grinding, and slurry of the zirconia powder with nonaqueous solvent is shaped and fired.

Abstract: An electrochemical device comprising at least one electrochemical cell having a planar solid electrolyte body, and a first and a second electrode one of which is disposed on the solid electrolyte body. The device has a measurement-gas space communicating with an outside space for introducing a measurement gas, and a reference-gas space into which a reference gas is introduced. The first and second electrodes are exposed to the measurement-gas and reference-gas spaces, respectively. The measurement gas is introduced into the measurement-gas space with a diffusion resistance to molecules of a selected component of the measurement gas. The measurement-gas and reference-gas spaces are juxtaposed in spaced-apart relation with each other in substantially the same plane parallel to the planar solid electrolyte body.

Abstract: An oxygen sensor according to the present invention comprises a tumbler-shaped solid electrolytic element formed of an oxygen-ion-conductive metal oxide. A first electrode and a lead electrically connected thereto are formed on the outer peripheral surface of the element which is exposed to exhaust gas. A second electrode is fixed to the inner peripheral surface of the element which is exposed to the atmosphere. The element is held by a ring-shaped metallic holder. The holder and the first electrode are electrically insulated from each other. A conductive metallic pipe member is disposed between the element and the holder. One end of the pipe member is electrically connected to the lead by means of a conductive metal ring. A partition wall extends integrally from one end of the pipe member, defining between its inner surface and the other peripheral surface of the element a space for housing the conductive metal ring between the pipe member and the lead.

Abstract: Apparatus and method for detecting and measuring hydrogen and compounds capable of dissociating into or combining with hydrogen ions using a solid electrolyte concentration cell. A solid reference substance is used in place of a reference gas. A novel solid electrolyte membrane is used which comprises an organic polymer-inorganic compound blend prepared by admixing an organic polymer such as poly(vinyl alcohol) with a heteropoly acid or salt thereof such as dodecamolybdophosphoric acid or uranyl orthophosphate in a mutually miscible solvent.

Abstract: A rod-like electrical heating element is incorporated in the interior of a tubular solid electrolyte sensor connecting zones of the heating element are disposed on the end face thereof remote from the sensing end. Electrical connecting parts are pressed against the connecting zones of the heating element by means of a spring element. These electrical connecting parts are in electrical contact with the connecting cable of the gas sensor via conductor wires, leads or other connecting means.

Abstract: A gas measurement probe has a casing (11) equipped with a closure shell (17) on its end away from the gas to be measured. At the other end of the casing, within its longitudinal bore, a sensor element (24) is held fast and tight in the casing. A rod-shaped part carrying a heater element fits within the sensor element and extends out of it at its end away from the gas to be measured to an extremity near which contact areas are provided on its periphery. On these contact areas, resilient connection wires lie under mechanical bias. These wires, between the loops bearing against the contact surface and their ends are bent in Z or sinuous shape so as to secure them against pulling, twisting and shaking forces. These connection elements and also another conductor running in the probe cooperate with an indexing feature of the rod-shaped element, such as a suitable groove to secure the rod-shaped component against twisting.

Abstract: A gas concentration sensing or pumping device is formed of a body of solid electrolyte material which exhibits ionic conduction when the concentration of gas is different between first and second surfaces of the body, or which, upon application of a voltage across the body, will cause gas on one side of the body to be pumped to the other side. A thin film of a composition comprising an element selected from the group consisting of rare earth elements, alkaline earth metals, Ga Pb, In, Sn, Ti, Mo and W wherein Bi is the predominant element is formed on a major surface of the body to enhance conductivity at the electrode/body interface. Conductive electrode layers are formed over the film and an opposing major surface. The conductive layers may be formed of porous LaCrO.sub.3 and the body may be formed of ZrO.sub.2, CeO.sub.2 or ThO.sub.2. An apertured disc or a layer of gas permeable material is formed over the sensor.

Abstract: In a heating system for heating a ceramic body suitably adapted for, but not limited to, a detector to measure the oxygen concentration of a gaseous mixture such as automobile exhaust gas by using the principle of an oxygen concentration cell made of an oxygen ion conductive solid electrolyte body with electrodes mounted on opposite surfaces thereof, the inventive heater or detector and the method use AC voltage electrode means provided on the solid electrolyte body to apply an AC voltage thereto for heating the heater or detector.

Abstract: A heating element comprises a resistor comprising a plurality of fine particles or thin films having a negative temperature coefficient of electrical resistance, and highly resistant region layers interposed between the fine particles or thin films, at least two separate electrodes arranged in contact with different particles or layers of the resistor, and means for applying across said electrodes an AC electric voltage, said means operable at AC frequencies which are not lower than a frequency whose complex impedance characteristics which when graphed in the manner shown in FIG. 4 hereof correspond to point B of said graphed complex impedance characteristics. This heating element has the following merits that it can be formed into an optional shape, is low in the power consumption, can be rapidly heated, has temperature self-adjusting performance and temperature detecting performance and is excellent in the durability.

Abstract: The disclosed heater with solid electrolyte has a resistor embedded in or tightly secured to a solid electrolyte and an AC power source connected to the resistor, so that heat is generated both in the resistor by an alternating current from the AC power source and in the solid electrolyte by an alternating current flowing therethrough depending on the temperature-sensitive resistance of the solid electrolyte being heated by the resistor.

Abstract: An oxygen sensor element with a ceramic heater, having a cylindrical element body formed of an oxygen ion permeable solid electrolyte with one end closed, inner and outer electrodes formed on the inner and outer surfaces of the element body, and an electrode protective layer covering at least one of the inner and outer electrodes, the ceramic heater including a bar-like ceramic core member, a ceramic covering layer which covers the outer surface of the ceramic core member and a heating member disposed in the interface between the core member and the covering layer.

Abstract: In the invention, an electrochemical cell including an oxygen reducing cathode, an oxygen generating anode and an electrolyte, and having both a deoxygenating function and an oxygen generating function is coupled to a chamber in such a manner that, when the oxygen concentration in the chamber is much higher than a predetermined value, the deoxygenating function is utilized to decrease the oxygen concentration and when the oxygen concentration in the chamber is much lower than the predetermined value, the oxygen generating function is utilized to increase the oxygen concentration so that the oxygen concentration in the chamber is maintained at the predetermined value.

Abstract: The invention provides a method for the continuous monitoring of the oxygen or hydrogen concentrations in a steam system with a solid electrolyte oxygen analyzer. The operating temperature of the analyzer is adjusted to about 500.degree. C. and the reference gas used for the analyzer is air or oxygen-inert gas mixture. Under operating conditions, an oxygen or hydrogen level of low parts per billion in superheated or saturated steam can be identified and measured. This technique is specifically useful for continuously monitoring the air inleakage, that is, the oxygen contents in steam and for controlling the corrosion intensity that is, the hydrogen levels in steam in, for example, steam turbine systems in power plants.

Abstract: An oxygen sensor having a bar-shaped heater inserted in an elongate bore formed in a tubular body of solid electrolyte which has porous platinum electrodes on its inner and outer surfaces and which is supported by a housing such that its closed end portion is exposed to exhaust gas and such that the elongate bore is gas-tight with respect to the exhaust gas. The bar-shaped heater comprises a heating resistor having a positive temperature coefficient, a ceramic body carrying the heating resistor so as to embed the latter, and a pair of lead wires. The ceramic body has on its periphery a pair of terminal pads connected to the heating resistor. The ends of the lead wires are brazed to the terminal pads with a brazing material containing silver. The ceramic body further has a pair of equipotential members disposed outwardly of the pair of terminal pads to enclose at least portions of the peripheries of the pads which are opposite to each other.

Abstract: An exhaust gas sensor (10) is disclosed which includes a sensor element (12) and a member (48). The member (48) includes a hollow tube (50) and a seal disk (58). The seal disk (58) is urged into sealing engagement with an annular surface (14) on the sensor element (12) to prevent exhaust gas from entering the interior (26) of the sensor element (12). The inner electrode (22) of the sensor element (12) extends to the annular surface (14) in an annular ring (88). The seal disk (58) is permitted to contact the inner electrode (22) about the entire periphery of the ring (88).

Abstract: A method of sputtering a platinum exhaust gas electrode onto a vitrified zirconia thimble for an electrochemical-type exhaust gas oxygen sensor. Porous high surface area films are consistently deposited at high rates. A DC magnetron cathode assembly having a magnetic field strength of at least 500 gauss across its target face is used at a sputtering power of about 4-9 kilowatts. A thimble-target spacing of less than about 3.0 cm, a pressure less than about 10 millitorr, a sputtering atmosphere consisting essentially of more than about 50 percent nitrogen and/or oxygen, an electrically isolated deposition surface, and an electrically floating reference electrode precoated on the zirconia thimble surface are used.

Abstract: An oxygen sensor having a bar-shaped heater inserted in an elongate bore formed in a tubular solid electrolyte body which has porous platinum electrodes on its inner and outer surfaces and which is supported by a housing such that its closed end portion is exposed to exhaust gas and such that the elongate bore is gas-tight with respect to the exhaust gas. The bar-shaped heater comprises a heating resistor having a positive temperature coefficient, a ceramic body carrying the heating resistor so as to embed the latter, and a pair of lead wires. The ceramic body has on its periphery a pair of terminal pads connected to the heating resistor. The ends of the lead wires are brazed to the pads with a mass of brazing material containing silver. An exposed surface of the brazing mass is coated with a metal layer made of metal which is different from silver or its alloy. The metal layer may be further coated with a heat-resistant layer.

Abstract: A heater-incorporating oxygen sensor includes a solid electrolyte oxygen sensor element comprising a solid electrolyte provided with electrodes on both its sides and a heater, said heater being a ceramic heater formed by sintering and embedding a metallized pattern in a ceramic insulator as one solid body, said ceramic heater being disposed within a space surrounded with said oxygen sensor element.

Abstract: An oxygen concentration regulator for regulating the oxygen concentration in gases comprises an oxygen ion conductive solid electrolyte body, at least two separate electrodes contacting the solid electrolyte body so as to form an electrolysis cell, said cell having complex impedance characteristics which when graphed exhibit a curve similar to that shown in FIG. 3 hereof, AC power supplying means for applying an AC electric voltage across said electrolysis cell, said AC power supplying means being operable only at an AC frequency which is not lower than a frequency whose complex impedance characteristics, when graphed in the manner shown in FIG. 3 hereof, correspond to point B of said graphed complex impedance characteristic curve, and means for affirmatively applying a DC current across said electrodes, said DC current regulating the oxygen concentration in gases.

Abstract: An oxygen concentration detector comprises an oxygen ion conductive solid electrolyte and electrodes provided thereon to form an oxygen concentration cell for detecting oxygen partial pressure in a gas such as exhaust gas from an internal combustion engine. The oxygen concentration detector according to the invention further comprises an AC power source supplying to the electrodes an AC having a frequency at which a polarization of AC component is caused mainly due to a polarization of the solid electrolyte to detect an impedance of the solid electrolyte and the electromotive force of the oxygen concentration cell.

Abstract: The disclosed oxygen concentration detector includes at least one resistive body and at least one semiconductor whose resistance varies with oxygen partial pressure, and an alternating current of a specific frequency is applied to the resistive body so as to raise the temperature thereof, which resistive body is adapted to heat the semiconductor.

Abstract: The disclosed oxygen sensor comprises a plate-like oxygen pump element with electrodes, a plate-like oxygen concentration cell element having electrodes disposed in parallel alignment with those of said pump element, and an intermediate board disposed between said two elements and having a hole defining a cavity between electrodes of said two elements, said intermediate board further having passages bored therethrough so as to communicate said cavity to outside of said oxygen sensor.

Abstract: The disclosed oxygen sensor includes three plate-like elements disposed in parallel and a heater, i.e., an oxygen pump element with electrodes and said heater disposed adjacent thereto, an oxygen concentration cell element with electrodes, and an insulating board disposed between the first two elements and having a hole bored therethrough at a position between the opposing electrodes of the first two elements so as to define a cavity therebetween, said insulating board further having at least one passage communicating said cavity to outside of said oxygen sensor.

Abstract: The disclosed oxygen concentration detector includes a plurality of resistive bodies at least one of which forms an oxygen concentration cell, and an alternating current of a specific frequency is applied to a selected resistive body so as to raise the temperature thereof, said selected resistive body being adapted to heat the oxygen concentration cell.

Abstract: The disclosed oxygen concentration detector includes at least one oxygen concentration cell and at least one oxygen-ion-conducting solid electrolyte, and an alternating current of a specific frequency is applied to the oxygen concentration cell so as to raise the temperature thereof, while a direct current is applied to the oxygen-ion-conducting solid electrolyte so as to control the oxygen partial pressure at one or two electrodes of the oxygen concentration cell.

Abstract: An oxygen concentration detector comprises an oxygen ion conductive solid electrolyte body and electrodes provided thereon to form an oxygen concentration cell for detecting oxygen partial pressure in a gas such as exhaust gas from an internal combustion engine. The oxygen concentration detector according to the invention further comprises an AC power source supplying to the electrodes an AC current having a frequency at which a polarization of alternating current component is caused mainly due to a polarization of the solid electrolyte body to heat it, and a DC power source supplying a direct current to the electrodes so as to control oxygen concentration on the side of at least one electrode of the oxygen concentration cell to detect its electromotive force.

Abstract: To provide access of gases to an electrode (39, 48) positioned on a flat plate (35) of solid electrolyte material, under controlled conditions, and while preventing access of gases to the electrodes where not desired, the electrodes are covered with a porous cover layer (42, 49) of sintered granular material, for example of zirconium dioxide, having a grain size of 10 .mu.m, and 25 .mu.m thick, with void or pore-formation material added thereto which, upon sintering, becomes volatile and leaves a porous structure. A gas-tight tunnel covering (44, 51) extends over the electrode and filler covering leaving an open space in those regions where the electrode is exposed to the desired gas, for example a test gas adjacent the sensing end (11/1) of the sensor, or oxygen from ambient air adjacent the connecting or terminal end (11/3) of the sensor, the respective gas to be applied to the electrode diffusing through the pores of the porous structure to the respective electrode.

Abstract: Apparatus and method for detecting and measuring chloride ion and therefore dissociable chlorine compounds using a solid electrolyte concentration cell. Applicable only to gaseous samples.

Abstract: A planar oxygen pumping device (10) has a first and second oxygen ion conductive solid electrolyte material layer (12, 18). A first electrode (16) is between, and in contact with, the first electrolyte material layers and the second electrolyte material layer. A second electrode (14) is on the first electrolyte material layer. A third electrode (20) is on the second electrolyte material layer. At least one of the first and second electrolyte layers has a porosity sufficient to establish at the first electrode (16) an oxygen concentration dependent upon the ambient atmosphere.