Abstract: Disclosed is an oxygen sensor and lead wire therefor. The lead wire has a first end contained within the oxygen sensor and a second end outside the oxygen sensor, the lead wire comprising an electrically insulating wall portion having passage means for providing enhanced fluid communication between the interior of the sensor and the exterior thereof. According to preferred embodiments, such passage means comprises a bore or a passageway in the insulating wall portion.

Abstract: A rugged O.sub.2 microsensor constructed from Si, and Pt, Si.sub.3 N.sub.4 and ZrO.sub.2 thin films which is free standing and isolated from the silicon substrate in combination with a counter electrode and a heater in a bow-tie configuration. The sensor combines an integral heater made from platinum which is deposited on a silicon wafer as a thin film. The thin film heater heats a small yttria-stabilized zirconia sensor that sends a signal proportional to the amount of oxygen in the ambient environment through a counter electrode. The sensor and heater are supported on the silicon wafer by a thin layer of silicon nitride.

Abstract: In a method of measuring humidity of an oxygen-containing gas by using an electrochemical cell, firstly an voltage is applied across the pair of the electrodes to obtain a characteristic curve between an intensity of the voltage and that of electrical current, the characteristic curve continuously originating from a first flat portion in which a first diffusion limit current generally remains constant within a predetermined voltage range, and ending up in a second flat portion in which a second diffusion limit current generally remains constant within a predetermined voltage range. Secondly each value of the first diffusion limit current and the second diffusion limit current is read out, and an arithmetic ratio of the first diffusion limit current to the second diffusion limit current is calculated to obtain the humidity of the gas.

Abstract: An oxygen sensor includes a hollow tubular element made of a solid electrolyte capable of conducting oxygen ions. The inner surface of the element is exposed to the atmosphere, and the outer surface thereof is exposed to an exhaust gas of which the oxygen concentration is to be detected. First and second electrodes are arranged on the inner and outer surfaces of the element, respectively. The second electrode is provided with a coating which contains a catalyst for causing and promoting a water gas reaction of carbon monoxide contained in the exhaust gas approaching the second electrode. Alternatively, a large number of pellets containing the catalyst are charged in the space between the tubular element and a protective tube surrounding the element.

Abstract: An oxygen sensor having an excellent durability against poisoning by Si is provided by adhering at least one oxide of Mg, Ca, Sr or Ba on the surface or in the pores of the protective layer covering the measuring electrode of the oxygen sensor.

Abstract: A housing for a fast exhaust gas sensor for cylinder-selective lambda measurements in an internal combustion engine comprises a hollow-cylindrical housing having at least two slot shaped openings that are arranged rotationally symmetrical over the circumference of the wall of the housing and extend parallel to the axis of the housing. Each of the slot shaped openings have edges that are overlapping in the fashion of a venetian blind so that the rotational symmetrical arrangement of the openings allows the housing and the exhaust gas sensor mounted within the housing to be integrated in an arbitrary rotational attitude relative to the exhaust gas stream in a pipe of a system.

Abstract: A gas measurement sensor (10) which sealingly encloses an axially oriented sensor (27) having an elongated, planar shape in the longitudinal bore (19) of its metal housing (11); while the section (27/1) on the gas measuring side of the sensor (27) has at least one sensor element (38) and possibly heating elements, the end section (27/3) on the connecting side is provided with layered contact surfaces (36), which are in contact with the sensor elements (38)/heating elements via strip conductors (37). A connector plug (43) surrounding the sensor (27) on the connecting side consists of a contact element support (44), an opposite wall (45), contact elements (46) and an annularly-shaped spring element (47); because of its mechanical pre-stressing, the spring element (47) presses the contact elements (46) of the contact element support (44) and of the opposite wall (45) against the contact surfaces (36) of the sensor (27).

Abstract: A bottomed, inner cylindrical member 21 is placed around a sensor element 2, and a bottomed, outer cylindrical member 24 is located around this inner cylinder 21. The inner cylinder 21 includes a hole 21a at a location opposite to the electrode of sensor element 2, and the outer cylinder 24 includes holes 24a and 24b at locations that are not opposite to the hole 21a. Between the inner and outer cylinders 21 and 24, there is a gap wide enough to prevent water from staying therebetween due to surface tension. Water entering the sensor assembly through the holes 24a and 24b in the outer cylinder 24 is immediately discharged out of the holes 24a and 24b through the gap between the outer and inner cylinders 24 and 21. Water, even when entering the outer cylinder 24, is unlikely to impinge directly on the sensor element 2 built in the inner cylinder 21.

Abstract: A sensor is disclosed for detecting the relative air/fuel ratio of the exhaust gas from an internal combustion engine. The sensor includes a housing which defines a closed interior chamber. An oxygen diffusion cell constructed of a solid electrolytic material has one side exposed to the exhaust gas and a second side exposed to the housing chamber so that oxygen ions flow through the diffusion cell in dependence upon the relative oxygen concentration in both the exhaust gas and the internal air chamber. A sense cell constructed of a solid electrolytic material also has one side exposed to the air chamber and a second side exposed to a substantially constant source of oxygen, such as the atmosphere. Thus, oxygen ion flow through the sense cell varies as a function of the oxygen concentration in the air chamber and thus of the oxygen concentration in the engine exhaust gas.

Abstract: An improved expendable oxygen sensor particularly useful for measuring the dissolved oxygen content of an aluminum killed, high silicon steel bath is disclosed. The device has the typical closed end tube of solid electrolyte containing oxygen reference material, but differs from previous sensors in that a shield is provided which protects the solid electrolyte from being in contact with the bath until the solid electrolyte has had a chance to heat up more closely to the temperature of the steel. This shield, in one form, consists of a closed end tube positioned to surround the solid electrolyte and spaced from the solid electrolyte in order to prevent erroneous outputs from the sensor due to oxidation of the shield material.

Abstract: An air-fuel ratio sensor which includes a sensing portion made of a solid electrolyte exposed to exhaust gas from an internal combustion engine and a microprocessor for executing a predetermined processing on the basis of an output voltage of the sensing portion to identify an air-fuel ratio of fuel mixture supplied to the engine, in which a voltage deviation is obtained between the output voltage of the sensing portion and a reference voltage, which is provided for every temperature of the sensing portion and in accordance with a target air-fuel ratio preset in advance for an air-fuel ratio control, whereby the air-fuel ratio of the fuel mixture is identified on the basis of the thus obtained voltage deviation.

Abstract: The invention provides an air/fuel ratio sensor, including an electrochemical sensor cell and an electrochemical pump cell, which shows both a quick response and a stable limiting current. This is realized by limiting the ratio of the area a of a region A to the area b of a region B on the inner electrode of the electrochemical sensor within a specified range, 0<a/b.ltoreq.0.1. Here, the region A corresponds to a region C within a 0.5 mm distance from the end of the gas diffusion hole except on the 0.5 mm distance line on the inner electrode of the electrochemical pump cell, and the region B corresponds to a region D or the complement of the region C on the inner electrode of the electrochemical pump cell.

Abstract: The present invention relates to an oxygen sensor, in which in order to be strong against vibration and shocks as well as to make rapid heating possible and to be capable of rapidly performing correct detection, the oxygen sensor provided is composed of a sensor element having a body portion and a thin portion which is thinner than the body portion, a detecting element is formed at the thin portion for measuring oxygen concentration, and an exothermic element is provided for heating the detecting element.

Abstract: A system for use in sensing the oxygen content of an industrial furnace gas typically containing hydrocarbons or hydrogen is disclosed. The system utilizes a conventional automotive EGR oxygen sensor probe positioned in an especially configured housing employing downstream flow regulating means in combination with an orificing plate in the housing to provide uniform distribution of the endothermic gas at a low temperature about the sensor to insure accurate sensor readings with minimal carbon deposition. The electrical contacts at the oxygen sensor's inner and outer electrolyte surfaces are periodically switched to an electrical power supply to cause current to flow through and heat the electrolyte to elevated temperatures while air is flowed over the electrolyte's surfaces to achieve burn out of any carbon deposits and restore the life of the oxygen sensor probe.

Abstract: An oxygen probe assembly comprising an oxygen sensor (5) and means (8, 3) for directing a test gas and reference gas to the appropriate electrodes (7, 1) of the sensor, said assembly having associated therewith catalyst means (13, 6) arranged so that the test gas, the reference gas, or both said gases are separately contacted with the catalyst means before approaching the working surface(s) of the electrodes, whereby combustibles in the gases are oxidized; and/or means whereby the test gas, the reference gas, or both of said gases are conveyed to the said working surface(s) by way of a path (10, 4) which is of sufficient length to allow the said gas or gases to attain thermodynamic equilibrium at the probe temperature before coming into contact with the said working surface(s).

Abstract: An electrochemical device such as an oxygen sensor comprising: a plurality of solid electrolyte bodies; at least one pair of electrodes, each pair being disposed such that the electrodes are held in contact with the solid electrolyte bodies separately; at least one conductor sandwiched by two adjacent conductors of the solid electrolyte bodies; and at least one electrical insulation layer. A substantive portion of at least one side of the conductor indirectly contacts one of the two adjacent solid electrolyte bodies via the electrical insulation layer which is disposed therebetween, whereby the conductor is protected from direct contact with the associated solid electrolyte body. The insulation layer further serves to prevent noises which could otherwise be produced due to leakage current from the conductor. The conductor may be a lead connected to one of the electrodes, or to a heater for heating a portion of the solid electrolyte body adjacent the electrodes.

Abstract: A waterproof type oxygen sensor including a sensor element having electrodes on inner and outer surfaces, respectively, a housing for housing the sensor element, a gas-tightly sealed section arranged inside the housing for isolating the exhaust gases from air, and a water-repelling communicating section for communicating the air inside the gas-tightly sealed section with surrounding air. The inner and outer electrodes are adapted to contact air and exhaust gases, respectively. In the oxygen sensors, Y.gtoreq.10X.sup.0.35 in which X and Y are a value obtained by expressing the gas-tightness of the gas-tightly sealed section as an amount of a gas passing the gas-tightly sealed section and an amount Y of a gas passing the communicating section, respectively.

Abstract: A protective tube of metal resistant to corrosion from hot gas surrounds and is spaced from a closed-end ceramic sensor body within which is an electrical heater. The protective tube extends beyond the end of the sensor body and has an annular groove at its open end, which bulges into the space enclosed by the tube and the outer end of which provides a flange perpendicular to the axis of the tube a fine metal screen may be provided across the open end of the tube for incepting droplets of water that may sometimes be present in the gas to be measured. The open end of the protective tube may be only slightly constricted by the groove or, in another embodiment, it may taper down in a rounded fashion to a narrower opening.

Abstract: A method of treating a porous body in a gas concentration sensor to regulate the gas diffusion. The porous body is impregnated with a impregnant containing a component that adheres to or binds with the pore surfaces. The component may be a metal salt, examples of which are Al(NO.sub.3).sub.3, CaCl.sub.2 and H.sub.2 PtCl.sub.2. A colloidal solution may be used.

Abstract: In an oxygen sensing unit, an oxygen sensing cell with a closed outer end is encircled by a side wall of a protective shell or shield, and recessed from an open mouth of the shell. The cell and shell are mounted in a plug made up of a closure cap with an externally threaded section and a plug body with an internally threaded section complementary to the externally threaded section of the closure cap, the two parts of the plug cooperating to hold and compress the shell and cell, mediately or immediately, and permit the removal and replacement of the cell.

Abstract: An air/fuel ratio sensor with a solid electrolyte oxygen pump and oxygen sensor defining a closed space therebetween. At least in the oxygen pump, porous electrodes sandwich an ionic oxygen conductive solid electrolyte. The voltage impressed on the electrodes of the pump is limited to a predetermined level, e.g., 6 V, in order to prevent blackening and cracking.

Abstract: A water-proof type oxygen sensor including a sensor element having inner and outer electrodes at inner and outer surfaces, respectively; a metallic cap for housing the sensor element; a gas-tight sealing member provided in the cap for isolating the exhaust gases from the air; communicating openings provided in the cap for communicating a space inside the cap with the air; and a communicating member arranged around the outer periphery of the communicating openings and having gas permeability and water-repellent property. The inner and outer electrodes are adapted to contact with air and exhaust gases. The communicating member is cylindrical and is fixed to the metallic cap through a metallic fixing member having a coefficient of thermal expansion almost equal to that of the metallic cap.

Abstract: An electrochemical device having an oxygen-ion conductive solid electrolyte body, a plurality of electrodes formed on the solid electrolyte body, an electrically insulating ceramic layer formed on the solid electrolyte body, a heater disposed such that the heater is electrically insulated by the ceramic layer from the solid electrolyte body, and a dc power source electrically connected to the heater for energizing the heater. At least one of the electrodes is electrically connected to a low-potential terminal of the dc power source. A voltage source is connected in a line between the above-indicated at least one electrode and the low-potential terminal of the dc power source, so that a potential of each of the at least one electrode with respect to a potential V1 at a point of connection of the above-indicated line to the low-potential terminal of the dc power source is maintained at a positive value which satisfies a formula, V1.ltoreq.

Abstract: In an oxygen sensor having a plate-shaped oxygen sensor element, a measuring electrode on the broader width surface of the plate-shaped sensor element, and a protective cover covering the plate-shape sensor element, wherein the protective cover has gas inlet holes for introducing a gas to be measured therein and guide plates for changing the direction of the flow of a gas to be measured. The gas inlet holes have different spacings compared to each other, the guide plates and the gas inlet holes have different lengths compared to each other in the axial direction of the protective cover, and/or the gas inlet holes have different opening extents compared to each other. Consequently, the oxygen sensor always can provide a homogeneous swirling flow of the gas to be measured in the protective cover as well as precise measurement of the gas and a constant .lambda. controlling point.

Abstract: A method for determining the concentration of a plurality of combustible gases in a gas stream comprises providing an electrochemical cell apparatus that includes an electrochemical cell in which a cavity is formed having a diffusion limiting port forming the entrance to the cavity. The cell has a process side in flow communication with a portion of the gas stream flowing into the cavity through the port, and a reference side in flow communication with a reference gas. The process side and the reference side of the electrochemical cell are separated by an electrolyte. The potential difference across the cell is adjusted to create a steady state electrical current flow.

Abstract: An oxygen gas concentration-detecting apparatus for use in an internal combustion engine comprising a plate-shaped substrate, a plate-shaped oxygen ion-conducting solid electrode for generating an electromotive force between a first surface contacted with air and a second surface contacted with an exhaust gas of the engine according to the difference between the concentrations of oxygen gases of the air and the exhaust gas, the solid electrode being laminated on the substrate, a pair of electrode members for taking out the electromotive force as a detection signal and a nitrogen oxide-reducing catalyst layer for promoting the reduction of nitrogen oxide arranged to cover the second surface of the oxygen ion-conducting solid electrode. By this apparatus, the concentration of oxygen gas inclusive of oxygen gas generated by reduction of nitrogen oxides can be precisely detected.

Abstract: An excellent oxygen sensor is provided, comprising; a sensor element having electrodes on inner and outer surfaces thereof, the electrode on the inner surface communicating to the atmosphere, and the electrode on the outer surface communicating to a gas to be measured; a metallic accommodating member accommodating the sensor element; and at least two airtight sealing portions arranged in the accommodating member for separating the gas to be measured from the atmosphere, at least one airtight sealing portion at the low temperature side of the oxygen sensor having a recessed portion formed under compression by pressing the outer surface of the metallic accommodating member after the formation of the airtight sealing portions by compressing the talc powder in the axial direction of the oxygen sensor. The oxygen sensor has splendid airtight sealing property of the airtight sealing portions containing compressed talc powders filled therein.

Abstract: An oxygen sensor including a detection element with electrodes for detecting an oxygen partial pressure, a metal member for containing the detection element, and an insulation spacer for supporting the detection element. The oxygen sensor further includes an insulating layer for covering the surface of a recess defined by the detection element, the metal member, and the insulating spacer, thus preventing the deterioration of insulation between the electrodes of the detection element and the metal member. The oxygen sensor of this invention can accurately detect the oxygen partial pressure for a long time.

Abstract: An oxygen sensor having construction of an upper open end portion plugged with a grommet through which lead wires are taken out of a protecting metallic cover. A resin grommet of a heat resistant resin such as Teflon, polyimide or the like is fitted in the upper open end portion of the metallic cover with a portion of the grommet being extended from upper open end portion of the metallic cover. A heat resistant non-metallic tube such as Teflon, polyimide, silicone rubber, fluororubber tube is closely fitted on the periphery of the extended portion of the resin grommet and the periphery of the upper end portion of the metallic cover and a metallic tube being closely fitted on the periphery of a portion of the non-metallic tube which is fitted on at least the metallic cover.

Abstract: An oxygen sensing probe of the type in which a sensor tip made of a solid electrolyte is secured within a supporting tube by an hermetic seal. The tip is made of yttria-stabilized zirconia; the tube is made of magnesium-aluminate spinel, calcia and zirconia; and the tip and the tube are bonded together by a fusion weld consisting of a eutectic mixture of the tip material and the tube material. The coefficient of thermal expansion of the tube material very closely matches that of the tip material so as to prevent the seal from cracking when the probe is cycled rapidly and repeatedly through a wide temperature range. A frustoconical shoulder on the sensor tip engages a slotted frustoconical seat within a tubular outer conductor to establish good electrical contact between the tip and the electrode while allowing gas to circulate freely past the tip.

Abstract: An oxygen sensor element including an oxygen ion conductive solid electrolyte body, and electrode layers formed on opposite surfaces of the oxygen ion conductive solid electrolyte body. The electrode layers are mainly constituted by a platinum group metal in which a refractory material is dispersed.

Abstract: In an oxygen sensor having a plate-shaped oxygen sensor element, a measuring electrode on the broader width surface of the plate-shaped sensor element, and a protective cover covering the plate-shaped sensor element and having gas inlet holes for introducing a gas to be measured therein, a cylindrical body is provided between the plate-shaped sensor element and the protective cover in such fashion as to avoid direct impingement of the gas to be measured upon the measuring electrode, whereby the oxygen sensor can provide good measurements of the gas with high precision and a constant .lambda. controlling point.

Abstract: An oxygen sensor is disclosed, which includes a planar sensor element and a metallic cover. The planar sensor element is provided with a detecting section at least at one of outer side surfaces thereof for detecting a gas to be measured. The detecting section is protected with the metallic cover. The metallic cover is provided with gas introduction openings for introducing the gas into the metallic cover. The gas introduction openings are arranged so as not to be opposed to the detecting section of the oxygen sensor element. Guide plates are provided at the gas introduction openings, respectively for swirling the gas inside the metallic cover in a given direction. The metallic cover is provided with a gas discharge opening at the bottom face thereof.

Abstract: A heater-built-in sensor for detecting a component in a measurement gas, including an electrochemical cell having a solid electrolyte body, and a pair of electrodes formed on the solid electrolyte body, a heater for heating at least a detecting portion of the cell which includes the measuring electrode, and a protective covering device disposed around the detecting portion. The covering device includes a gas-inlet portion for introducing the measurement gas to the measuring electrode, and a thermally insulating portion for preventing dissipation of a heat generated by the heater. The thermally insulating portion, which is separated from the gas-inlet portion, is adapted to surround the detecting portion so as to prevent the measurement gas from flowing to and from any parts of the detecting portion, except a part at which the measuring electrode is located.

Abstract: An air/fuel ratio (A/F) sensor for detecting the A/F over a wide range covering a lean region and a rich region which are partitioned by the stoichiometric A/F comprises a solid electrolyte made of an oxygen ion conductive metal oxide, first and second electrodes sandwiching the solid electrolyte and being operable by a predetermined voltage applied thereacross to ionize oxygen near the solid electrolyte and diffuse oxygen ions into the solid electrolyte, and a gas diffusion layer in the form of a porous sintered layer covering the second electrode and made of electrically insulative metal oxide fine particles having a mean particulate size of 1 .mu.m or less so that oxygen or molecules of other gas components in the exhaust gas can move through pores of the gas diffusion layer.

Abstract: Thermal shock reactions of a heated lambda probe owing to the impact of liquid droplets on the heated ceramic probe body during cold starting, which phenomenon can lead to a fracture of the ceramic probe body, are avoided, and a better representativeness of the signals transmitted by the lambda probe is achieved, in that a gas deflector plate is arranged before the lambda probe in the exhaust gas flow, as seen in the direction of flow of the exhaust gases, in such a way that the lambda probe lies in its Lee.

Abstract: A solid NaCl or KCl electrolyte electrochemical concentration cell assembly (20) for measuring monitored gases (38) containing oxygen or a chlorine containing component is divided into two identical alkali ion conductive half cells (22) and (24) where each half cell has solid electrolyte (23) and (25) that consists essentially of NaCl, KCl, or their mixture and is secured to opposite surfaces of the closed end of a solid membrane (36) exhibiting sodium or potassium ion conductivity. The membrane (36) effectively isolates the monitored gases (38) contacting one half cell from a reference gas environment (40) contacting the other half cell.

Abstract: Apparatus for measuring the concentration of oxygen in exhaust gases. A gas sensor element of yttria-stabilized zirconia (Y.sub.2 O.sub.3 -ZrO.sub.2) has at one end a gas pump of two chambers separated by intervening Y.sub.2 O.sub.3 -ZrO.sub.2 with an orifice extending between each chamber and the exterior of the gas sensor element. Two platinum electrodes of a first set face one chamber and two platinum electrodes of a second set face the other chamber. The gas sensor element is mounted in an insulating mounting collar in close contact with two ceramic heaters of resistance heating elements on silicon nitride substrates. The mounting collar is clamped between a shield member encircling the gas pump of the sensor element and a housing member by threaded clamping nuts. The shield member has one or more apertures therein to admit exhaust gases to be analyzed to the gas pump of the sensor element.

Abstract: An electrolytic oxygen sensor in which the atmosphere is admitted to one side of the solid electrolyte through an air-permeable spacer through a dual concentric tube structure. Holes are formed in the inner tube to complete the air flow to the atmosphere. The small size of the holes prevent the entry of water and oil contaminants.

Abstract: An oxygen concentration measuring device having a very small size detecting portion formed of unitary lamination of plate shaped members of an oxygen sensing element, a heater member and/or a temperature detecting member. The element comprises an oxygen concentration cell and a temperature compensation means for compensating a setting voltage to which an EMF generated by the concentration cell is compared. The detecting portion is provided with a printed contact terminal and housed in a probe equipped with a protecting tube. The printed contact terminal of the detecting portion is arranged to mate with a connecting element housed in a funnel-shaped contact member so as to allow easy mounting and detaching.

Abstract: An electrochemical device such as an oxygen sensor comprising a plurality of solid electrolyte bodies, at least one pair of electrodes, each pair being disposed such that the electrodes are held in contact with the solid electrolyte bodies separately, at least one conductor sandwiched by two adjacent ones of the solid electrolyte bodies, and at least one electrical insulation layer. A substantive portion of at least one side of the conductor indirectly contacts with one of the two adjacent solid electrolyte bodies via the electrical insulation layer which is disposed therebetween, whereby the conductor is protected from direct contact with the associated solid electrolyte body. The insulation layer further serves to prevent noises which could otherwise be produced due to leakage current from the conductor. The conductor may be a lead connected to one of the electrodes, or a heater for heating a portion of the solid electrolyte body adjacent to the electrodes.

Abstract: To accurately control access of measuring gas into the measuring electrode (15) of a polarographic sensor having a tubular body (12) of solid electrolyte material, the tubular body is enclosed within a protective sleeve (38) closed at one end and embodying a diffusion resistance element, or diffusion resistance zone (43/1, 43/2); if the sleeve is of metal, a separate diffusion resistance element, for example, made of aluminum oxide or spinell may be used; if the sleeve is made of ceramic, the end portion may be thickened and the diffusion resistance zone formed therein, for example, by micropores or microchannels or microducts extending therethrough.

Abstract: An excellent oxygen sensor having a heater with improved durability of the connecting portions of the lead terminals of the heater, is provided.

Abstract: A terminal member (120) for an electrolyte sensor (24) having a first diameter section (122) separated from a second diameter section (124) by a shoulder (126). A stepped axial bore (138) extends from a second end (134) forward a first end (132). First and second passages (128 and 130) extend from the first end (132) to the second end (134). An axial slot (136) extends through the second diameter (124) to the stepped axial bore (138). First and second grooves (156 and 158) located on the periphery of the first diameter (122) extend to a first radial slot (160). A second radial slot (162) is offset from the first radial slot (160). The first and second radial slots (160 and 162) position terminals (164 and 164') connected to a heater member (92) located in bore (138) while first and second contact rings (142 and 144) are located on shoulder (126) and (140) to provide isolation for electrical paths between an external surface (80) and internal surface (82) of an electrolyte sensor (24).

Abstract: An oxygen sensor is provided with an electrolyte tube formed in two parts, one part is an elongated tube and the other part is a sacrificial pellet which thermally insulates the tube from thermal shock which can cause cracks in the tube.

Abstract: To make it possible to exchange the solid-electrolyte ball (1) easily and quickly, while at the same time ensuring effective sealing between the support (3) and the ball (1), when it has been polluted by the atmosphere of a furnace, the probe comprises a sleeve (4) communicating with the atmosphere of the furnace via orifices (13) and having a stop (5) forming a measuring electrode. The ball is stressed up against the stop (5) by a support (3), while a shoe (12) pressed against the ball (1) by a rod (9) forms an internal electode. This rod (9) has a cavity (15), in which is accommodated a thermocouple (16) for measuring the temperature of the ball (1), and longitudinal ducts for the passage of wires (18, 19, 24) for connection to the thermocouple (16) and the shoe (12) and for conveying reference air into the region of the shoe. The spherical shape of the contact surface between the ball (1) and the support (3) ensures effective sealing.

Abstract: An oxygen sensor (10) having an electrolyte sensor (40) located in a metal shell (14) and an insulating terminal (102) located in a metal sleeve (72). The metal sleeve (72) is secured to the metal shell (14) to define a reference chamber (68) adjacent the interior of the electrolyte sensor (46). A closed end (74) on the sleeve (72) has a plurality of openings (76, 76.sup.1 . . . 76.sup.n) surrounding a central opening (78). A porous filter (90) has a base (92) that is continually urged against end (74) by the action of spring (118) on terminal (102). A grommet (124) located in the central opening (78) has a cylindrical body with a flange (136) that radially engages filter (90) and a series of lands (132, 132.sup.1 or 132.sup.n) that form a plurality of sealing surfaces on lead (12) that connects the electrolyte sensor (46) with a controller.

Abstract: A sensor (24) having a metal shell (30) joined to a sleeve (96) to locate a heater (92) in a thimble of an electrolyte member (72). A sealed joint is produced between the sleeve (96) and metal shell (30) to define a sealed reference chamber (118). A porous filter (112) in the sleeve (96) prevents water in environmental air from entering the reference chamber (118). Leads (106') and (106") which pass through a seal (123) adjacent the porous filter (112) are connected to terminals (164 and 164'). Terminals (164 and 164') located in a terminal member (120) position a heater (92) within chamber (118) and the electrolyte member (72). Leads (106 and 106.sup.n) which pass through the porous filter are connected to contact rings (142 and 144). Contact rings (142 and 144) are connected to an external and internal coating (80 and 82) on the electrolyte member (72).

Abstract: A sensor (24) having a metal shell (30) joined to a sleeve (96) to locate a heater (92) in a thimble of an electrolyte member (72). A sealed joint is produced between the sleeve (96) and metal shell (30) to define a sealed reference chamber (118). A porous filter (112) in the sleeve (96) prevents water in environmental air from entering the reference chamber (118). Leads (106') and 106") which pass through the porous filter (112) are connected to terminal (164 and 164'). Terminals (164 and 164') located in a terminal member (120) position a heater (92) within chamber (118) and the electrolyte member (72). Leads (106 and 106.sup.n) which pass through the porous filter are connected to contact rings (142 and 144). Contact rings (142 and 144) are connected to an external and internal coating (80 and 82) on the electrolyte member (72).

Abstract: During the measurement of oxygen content of a gas with a solid electrolyte material capable of oxygen ion conductivity the electrolyte is heated to maintain a constant control temperature. If the ambient temperature changes, an offset or error is introduced into the oxygen measurement. An apparatus and method is provided to automatically compensate for any such offset. Thermocouple means are provided in series with the electrolyte circuit so that a thermal emf if generated due to any differential between ambient and control temperatures. The thermocouples are arranged to generate a net thermal emf which opposes the emf generated by the electrolyte by an amount which automatically compensates for any offset due to the temperature differential. If the ambient and control temperatures are the same, there will be no offset and no net thermal emf.