Abstract: An arrangement of a sensor element of an electrochemical measuring sensor in a metallic housing is proposed, wherein the sensor element (13) in the form of a tube closed at one end rests with a metallic sealing ring (18) on a seal seat (16) implemented on the housing. The seal seat (16) is designed as a raised circular ring surface having a radius (r), with the sealing ring (18) orienting itself tangentially with respect to the radius (r).

Abstract: A method of monitoring and controlling thermal spraying methods for coating the surface of substrates. During the spraying process, a substrate surface temperature is measured as a characteristic variable for the transferred layer mass or layer thickness, and, in the event of deviations from the nominal value, at least one method parameter that is significant for the transferred layer mass or layer thickness is changed. The method permits the creation of layers having a predetermined transferred layer mass or layer thickness and a narrow layer thickness distribution over the coated surface.

Abstract: A sintered layer system, includes an ion-conductive solid electrolyte layer which has a high oxygen ion conductivity and which is comprised of a solid electrolyte material comprising at least one oxide of tetravalent metals and at least one stabilizer oxide; and at least one functional layer which comprises a mixture of the solid electrolyte material and at least one further material, wherein the solid electrolyte material of the ion-conductive solid electrolyte layer and the solid electrolyte material of the at least one functional layer are comprised of nanocrystallites having a mean diameter of <100 nanometers.

Abstract: A method for fabricating a high-activity cermet electrode which is applied on an exhaust gas sensor including an oxygen ion conducting solid electrolyte, which is composed of a cermet material composed of at least one catalytically active material and at least one oxygen ion conducting ceramic material, which is bonded to the solid electrolyte of the exhaust sensor by co-sintering the cermet electrode and the solid electrolyte at a temperature ranging from 1300.degree. to 1600.degree. C. to provide a porous cermet electrode, and which contains at least one further catalytically active material which is embedded in the pores of the porous cermet electrode after co-sintering, the method including bonding together an unsintered solid electrolyte which conducts oxygen ions and a cermet electrode by co-sintering at from 1300.degree. to 1600.degree. C. to provide a porous cermet electrode; and subsequently introducing at least one further catalytically active material into pores of the porous cermet electrode.

Abstract: Proposed is an electrochemical measuring instrument (10) for determining the oxygen content in gas mixtures, in particular exhaust gases from combustion engines, with a sensor element (14) that is installed potential-free in a metal casing (11). The sensor element (14) has an oxygen ion conducting solid electrolyte body (23) in the shape of a tube closed on one side, with electrodes (25, 26) and connections (27, 28), and is fitted inside the casing (11) with a metal sealing ring (20). The connection (27) which runs along the outer surface of solid electrolyte body (23) is covered with an electrically insulating layer (21), at least in the area surrounding sealing ring (20). In addition, a ductile cover layer (31) that spans solid electrolyte body (23) is applied over insulating layer (21) in the area surrounding sealing ring (20), with which the sensor element (14) rests on sealing ring (20).

Abstract: A measuring sensor for determining the oxygen content in gas mixtures including exhaust gases of internal combustion engines, includes a first electrochemical pump cell and a second electrochemical pump cell; an internal reference gas source; a measuring gas chamber which is connected to the gas mixture; electrodes for the first and the second pump cell; a first pumping voltage (U.sub.P1) for the first pump cell and a second pumping voltage (U.sub.P2) for the second pump cell; wherein oxygen is pumped into the internal reference gas source by means of the first pumping voltage, wherein a pumping current is driven by the second pumping voltage and is measured as a measure for the partial oxygen pressure, wherein the first pumping voltage (U.sub.P1) and the second pumping voltage (U.sub.P2) are set such that more oxygen is pumped into the reference gas source by way of the first pumping voltage (U.sub.P1) than is pumped out of the reference gas source by the second pumping voltage (U.sub.

Abstract: A ceramic which is thermal shock resistant and which is a sintered, homogeneous mixture of first and second ceramic powders, including a first ceramic powder which is based on at least one tetravalent oxide selected from the group including zirconium dioxide, hafnium dioxide, and thorium dioxide, and which is further composed of at least one stabilizer oxide selected from the group including oxides effective to stabilize the at least one tetravalent oxide; and a second ceramic powder which is based on at least one tetravalent oxide selected from the group including zirconium dioxide, hafnium dioxide, and thorium dioxide, which contains from 0 to 2.5 mole % of at least one stabilizer oxide based on that molar amount of Y.sub.2 O.sub.

Abstract: An electro-chemical measuring sensor (10) for determining the oxygen content of gases, in particular for determining the oxygen content in exhaust gases of internal combustion engines, with a potential-free disposed sensor element (14). The sensor element (14) has an oxygen-ion-conducting solid electrolyte body (23), preferably in the shape of a pipe or tube closed at one end, which has an exterior electrode (25) disposed on the exterior surface with a strip conductor (27) on the side toward the contact and also extending on the exterior surface, and which is inserted by means of a sealing ring (20) in a metal housing (11). The sensor element (14) has an electrically insulating layer (21) at least in the area of the sealing ring (20), which covers at least the strip conductor (27) in the direction toward the housing (11). The insulating layer (21) is formed from a mixture of a crystalline, non-metallic material and a glass-forming material.

Abstract: The electrochemical sensor for determination of an oxygen content of exhaust gases, includes a probe element including a tube made from a raw material mixture consisting essentially of an ionically conductive solid electrolyte; an outer electrode located on the outer surface of the tube; a substantially pore-free conductor strip layer located on the outer surface, connected to the outer electrode, and extending toward the open end, the conductor strip layer having a portion in close proximity to the tube open end; and a substantially pore-free cover layer hermetically covering at least the portion of the pore-free conductor strip layer in close proximity to the open end of the tube, the cover layer being made from a cover layer material including the ionically conductive solid electrolyte. The cover layer material advantageously a sintering activity which is at least equal to that of the raw material mixture from which the tube is made.

Abstract: A limit current sensor for determining lambda values of a gas mixture includes a solid electrolyte layer comprised of a material which conducts oxygen ions; an anode provided on a surface of the solid electrolyte layer and having a surface opposite the solid electrolyte layer which is exposed to a gas which is one of the gas mixture being measured or a reference gas; a first pumping cell comprising the anode and a first cathode provided on a surface of the solid electrolyte layer opposite the anode; a second pumping cell comprising the anode and a second cathode provided on the surface of the solid electrolyte layer on which the first cathode is provided and spaced apart from the first cathode; a diffusion layer which is provided across the first cathode and the second cathode in contact therewith and along surfaces thereof opposite the solid electrolyte layer, and which is in communication with the gas mixture to be measured so that diffusion of the gas mixture to be measured through the diffusion layer occu

Abstract: An electrochemical sensor for determining the oxygen concentration in gas mixtures is proposed. The sensor has a solid electrolyte (10) with oxygen ionic conductivity, which has a measuring electrode (11) that does not catalyze establishment of equilibrium of the gas mixture and is exposed to the gas mixture. The measuring electrode (11) contains platinum and bismuth. The effect of these materials is that the free oxygen contained in the gas mixture is preferentially adsorbed, without reacting with the other gas components such as CO and HC.

Abstract: The invention relates to composite systems having at least two layers which comprise different inorganic, ceramic phases and are produced by cosintering of different, finely divided inorganic materials arranged in layers. The composite systems are characterized in that at least two adjacent layers comprise a dense phase largely free of macropores. The layers are durably bonded to one another by sintering together of particles of the different materials at the phase boundary or boundaries. The composite systems and the processes for the production thereof are used, for example, in the manufacture of gas sensors.

Abstract: A sensor element for determining concentration of at least one constituent of a gas mixture operates on an electro-chemical measuring process and includes a gas measuring chamber; a pair of electrodes and an electrode chamber located between the pair of electrodes; and a diffusion conduit adjoining the electrode chamber and having a gas input which connects with the gas measuring chamber, having a gas output which connects with the electrode chamber, and having at least one cross-sectional area including a height, w, and a length, L, which height, w, has a preselected minimum value, and which length, L, has a value which is equal to or greater than the preselected minimum value of the height, w.

Abstract: A polarographic sensor for determining concentration of certain components including oxygen or combustible fractions, such as hydrocarbons, hydrogen and carbon monoxide, in the exhaust gas of an internal combustion engine, includes a pump cell having an anode, a cathode, and an oxygen ion-conducting solid electrolyte provided between the anode and the cathode, wherein the cathode is provided with a diffusion barrier, wherein the anode is provided with a diffusion barrier, and wherein the concentration of the certain components is determined by measurement of a limiting current through the electrolyte and across one of the diffusion barriers to the corresponding anode or cathode.

Abstract: A sensor arrangement for determining at least one of gas components and gas concentrations of gas mixtures including CO, NO.sub.x and HC in exhaust gases of internal combustion engines, includes a measuring element which has a sensitive region; and a pump cell that includes a solid electrolyte and inner and outer pump electrodes which are opposingly disposed at least on the solid electrolyte and which effect an oxygen transfer to the measuring element, wherein the pump cell and the measuring element are spatially separated from one another, are located in different temperature zones during operation of the sensor arrangement, and are connected to one another by a diffusion segment through which oxygen can diffuse from the pump cell to the measuring element.

Abstract: An electrochemical measuring probe for determining the oxygen content of gases, in particular of exhaust gases of internal combustion engines, whose measuring probe body consists essentially of a solid electrolyte, for example stabilised ZrO.sub.2 and whose electrode exposed to the gas to be measured is a cermet electrode which is coated with a finely porous ion-conducting covering layer composed of an ion-conducting supporting matrix material having no sintering activity of the type standard for cermet electrodes the covering layer is covered by a porous protective layer. The ion-conducting porous covering layer appreciably increases the activity of the cermet electrode.

Abstract: A sensor for determining gas components and/or gas concentrations in gas mixtures, in particular in exhaust gases of internal combustion engines. The sensor has an oxygen pump cell and a measuring element having a sensitive region. Provided between the pump cell and the gas mixture is a diffusion path in which there are formed an oxygen gradient XO.sub.2 and a gradient X.sub.CO of the gas component to be determined, which extend respectively in opposite directions. The measuring element is positioned relative to the pump cell and the diffusion path in such a way that an excess of oxygen is present on the sensitive region of the measuring element.

Abstract: An electrical-discharge electrode, in particular a spark-plug electrode, having a main electrode body made of metal, the main electrode body, in particular at least its tip, is provided with an intermetallic phase composed of nickel aluminides, and a method of producing this electrical-discharge electrode.

Abstract: The invention relates to a measuring sensor having pump reference for measuring the oxygen content of gas mixtures, particularly exhaust gases of internal combustion engines. The sensor includes a measuring cell (A) and a reference cell (B) each having a pair of electrodes, with one of each respective pairs of electrodes being common to the two cells, and having a fixed electrolyte. Reference cell (B) has defined therein an internal oxygen reference zone which is hermetically sealed from the gas mixture and which is connected to the atmosphere by way of a pressure-equalization line. The measuring cell (A) and the reference cell (B) can be heated by heating apparatus to a temperature at which the fixed electrolyte has an ionic conductivity which is sufficiently high.

Abstract: A method is disclosed for the protection of catalytic converters for exhaust gas purification by measuring the temperature with a heat tone sensor suitable particularly for the implementation of the method, wherein a heat tone sensor composed of at least two NTC or PTC resistors and provided with a coating of a catalytically active material on the sensor in the region of at least one of these resistors is arranged ahead of the catalytic converter in the exhaust gas stream or a part thereof, with the catalytically active material initiating the same exothermal reactions as they take place in the catalytic converter employed for the exhaust gas purification. If the resistor is overheated due to an overly intensive exothermal reaction, resulting in a change in resistance, the heat tone sensor detects the drop in the throughput rate of the catalytic converter.