Abstract: A sensor for determining a concentration of gas components in gas mixtures having a first measuring electrode (mixed potential electrode) which has little or no catalytic effect on the establishment of an equilibrium in the gas mixture and a second measuring electrode (equilibrium electrode) which catalyzes the establishment of an equilibrium in the gas mixture as well as a solid electrolyte that is conductive for oxygen ions arranged between the two measuring electrodes, with the two measuring electrodes being exposed to the gas mixture. At least the first measuring electrode (16) is a cermet electrode, where at least one metal oxide component of the cermet electrode is capable of reversible incorporation of oxygen.

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: The invention describes a sensor element for determining the concentration of gas components in gas mixtures, in particular in exhaust gases of combustion engines, comprising at least one measured gas space (13) and at least one gas inlet opening (17) through which the gas mixture is conveyable to the measured gas space (13), and at least one diffusion barrier (12) arranged between the gas inlet opening (17) and measured gas space (13). The diffusion barrier (12) has at least one region (14, 14a, 16) that contains a catalytically active material for establishing equilibrium in the gas mixture, and is divided into a coarse-pore and a fine-pore portion.

Abstract: The invention describes a sensor element for determining the concentration of gas components in gas mixtures, in particular in exhaust gases of combustion engines. It includes at least one measured gas space (13) and at least one gas inlet opening (17) through which the gas mixture is conveyable to the measured gas space (13), and at least one diffusion barrier (12) arranged between the gas inlet opening (17) and measured gas space (13). The diffusion barrier (12) includes at least one layer (14, 14a, 14b) of catalytically active material for establishing equilibrium in the gas mixture.

Abstract: A sensor, particularly for determining the oxygen content in exhaust gasses of internal combustion engines, includes sensor element which is fixed in a metallic housing and a sealing flange which is integrally formed on the housing and rests on a sealing seat which is formed on an exhaust system. The sealing flange has two ring elements which are integrally formed on the housing and each have an inclined sealing surface, a hollow space being formed between the two ring elements inside the housing.

Abstract: The invention is directed to a method for detecting the oxygen content in a gas to be measured. At least one concentration cell operating in accordance with the Nernst principle is provided. The concentration cell includes a measuring electrode communicating with the gas and a solid electrolyte and a reference electrode connected to the measuring electrode through the solid electrolyte. A pump-current pulse is applied between the reference electrode and the measuring electrode and, directly after the end of each pump-current pulse, the current flow between the reference electrode and the measuring electrode is reversed in a pulse-like manner.

Abstract: In order to provide a method and arrangement for analytical determination of the relative amounts of exhaust gas components, except for water, but including hydrogen in the rich range or oxygen in the lean range, and for determining a &lgr; value, in which the exhaust gas sample can be taken at any arbitrary location, an arrangement is provided in which at least one portion of the exhaust gas is passed through a catalytic reactor (2, 22), a condenser (3,23) connected to the catalytic reactor to receive the gas passed through it, and, after passing through the condenser, the gas passes through an IR spectrometer and by a &lgr;-sensor. The oxidizable and reducible components of the exhaust gas are reacted with each other in the catalytic reactor which is heated to temperatures greater than 450° C.

Abstract: A measuring sensor, in particular for determining the oxygen content in exhaust gases of internal combustion engines, having a sensor element fixed in gastight fashion in a metal housing (14) and having a sealing flange (60) mounted on the housing (14) and resting on a sealing seat (76) embodied in an exhaust system (11). A union nut (80) is guided over onto the housing (14) and can be screwed into a thread (78) of an opening (70) provided in the exhaust system (11) and presses the sealing flange (60) against the sealing seat (76). The housing (14) has a housing part (12) on the side toward the gas to be measured and a further housing part (13) on the side toward the connection, and the sealing flange (60) is disposed on the housing part (13) on the side toward the connection and is shaped from the material of the housing part (13) on the side toward the connection.

Abstract: A gas sensor having a sensor element which is immobilized in gas-tight fashion in a metal housing. The gas sensor has a double-walled protective tube with an outer protective sleeve and an inner protective sleeve, each of which possesses openings for the entry and/or exit of gas. The inner protective sleeve forms a gas space into which the sensor element projects with a section at the measurement-gas end. The outer protective sleeve is a sleeve having a closed enveloping surface, the openings for the entry and/or exit of gas being arranged in the cavity at the end face of the sleeve. The gas space formed by the inner protective sleeve has, perpendicular to the extension direction of the sensor element, a rectangular cross section.

Abstract: The invention relates to a measuring instrument, particularly an electrochemical measuring sensor, having a sensor element arranged at a measuring point, which sensor element can be connected via electrical connecting leads with an evaluating circuit removed from the measuring point, with the electrical connecting leads being guided so as to be protected against external influences, especially against high temperature influences, at least in the proximity of the measuring point. At its end facing away from the sensor element (12), a protective device (24) receiving the electrical connecting leads (22) is provided with a connecting device (30) which can be connected to a connecting lead (54, 56) to the evaluating circuit.

Abstract: The invention relates to a device for detecting the oxygen content in a gas to be measured, wherein the device comprises at least one concentration cell which includes a measuring electrode, a solid electrolyte and a reference electrode. The measuring electrode communicates with the gas to be measured and is connected via the solid electrolyte to the reference electrode, which communicates with a reference gas volume. The reference gas volume is separated from the gas to be measured in such a way that a particle exchange between the reference gas volume and the gas to be measured is at least impeded. The output voltage of the concentration cell, which voltage can be tapped off between the measuring electrode and the reference electrode, represents a measure of the difference in the oxygen concentrations in the gas to be measured and in the reference gas volume.

Abstract: A method of determining at least one of gas constituents and gas concentrations of a gas mixture such as exhaust gas from an internal combustion engine includes producing a change in gas concentration of the gas mixture at a semiconductor gas sensor by pumping a variable supply of oxygen to the semiconductor gas sensor by means of a solid electrolyte pumping cell; detecting at least one reaction speed selected from the group consisting of adsorption speed and desorption speed caused by the change in gas concentration as a signal from the semiconductor gas sensor which is a reply function; evaluating the signal from the semiconductor gas sensor over time to provide a time response of the reply function; and comparing the time response of the reply function with a stored, standardized time response of different gas constituents whereby at least one of the gas constituents and the gas concentrations of the gas mixture are determined.

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: 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: 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.

Abstract: An electrochemical measuring sensor for the determination of the air/fuel ratio in exhaust gases of internal combustion engines both in the low-fuel and also in the fuel-rich range with a sensor element with an electrochemical oxygen concentration cell and an oxygen pumping cell with solid electrolyte base is proposed, in which the sensor element is arranged in a housing, capable of insertion in the exhaust gas pipe, in a manner such that the electrodes of the electrochemical oxygen concentration cell and of the oxygen pumping cell of the sensor element in the measuring sensor are situated outside the exhaust gas pipe, the communication with the atmosphere taking place via openings in the housing and the communication with the exhaust gas taking place via a diffusion slit. The sensor element is characterized by a particularly simple construction, free oxygen being available to the oxygen pumping cell both in the lean and also in the rich lambda range.

Abstract: A resistance probe is proposed for detecting gas compositions, particularly in the exhaust gases of internal combustion engines. This resistance probe has the advantage over prior art resistance probes that, with a short response time, it is considerably more aging resistant. This is accomplished in that the resistance layer configured as a semiconductor layer is introduced or sintered into recesses or slits provided for this purpose in the prefabricated sensor carrier body and above it is applied a porous, electrically non-conductive engobe or a protective layer structure in the form of a grid or raster. These measures enable the measuring gas to gain access to the semiconductor layer, but the semiconductor layer is simultaneously protected against corrosive, erosive and/or cavitative attacks from the exhaust gas.

Abstract: A sensor element for limiting current sensors for determination of the .lambda.-value of gas mixtures is proposed, which has at least one outer pumping electrode and one inner pumping electrode, on a solid electrolyte in platelet or foil form, conducting O.sup.2- ions, of which the inner pumping electrode is arranged in a diffusion channel for the measuring gas. It consists of a porous three-dimensional precious metal electrode having a supporting structure, the thickness of which electrode corresponds to the height of the diffusion channel. Characteristic of the inner pumping electrode is a greatly improved load-bearing capacity in comparison with electrodes of sheet-like design, whereby the service life of the sensor element is increased. A further advantage of the three-dimensional design of the inner pumping electrode is that it takes on a supporting function during lamination in the production of the sensor element by ceramic foil and screen printing techniques.