摘要:
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. In the course of production the insulating layer (21) is subjected to a thermal treatment above the melting temperature of the glass-forming material, in the course of which the insulating layer (21) forms a glaze filled with the crystalline, non-metallic material.
摘要:
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.
摘要:
An exhaust gas sensor which is exposed to exhaust gas, includes a measuring electrode; and a porous ceramic coating provided on the measuring electrode and comprised of at least two layers, a first porous ceramic layer which is provided on the measuring electrode and at least a second porous ceramic layer which is provided on the first porous ceramic layer and which is directly exposed to the exhaust gas, wherein the first porous ceramic layer contains getter substances for removal of substances that are harmful to the measuring electrode, and wherein the second porous ceramic layer is provided with one of a diffusion resistance or a catalytic effect relative to exhaust gas constituents such that, at the boundary of the first and second porous ceramic layers, a gas composition is present in use which is comprised of one of oxidizable or reducible gas constituents and which sets a control position for the exhaust gas sensor.
摘要:
A gas sensor, in particular a lambda probe, for ascertaining the pollutant and/or oxygen content in emission gases of internal combustion engines, having a housing accommodating at least one sensor element, the sensor element having a section on the terminal side and a section on the measuring-gas side, and having a connecting element that connects the sensor element, which has a plurality of electrically conductive contact areas, at its terminal-side section to a plurality of electrically conductive supply leads. The gas sensor has the feature of a connecting element which is formed from a spring element produced in one piece from ceramic material.
摘要:
A measuring sensor, in particular, for determining the oxygen content in exhaust gases of internal combustion engines, includes a ceramic molding arranged in a metal housing for the accommodation of a sensor element, in particular, planar, the sensor element being sealed by a seal element made of warm-deformable temperature-resistant material. The molded housing is designed in one piece and has a cylindrically shaped longitudinal hole on the connector side, around the sensor element, and the seal element is compressed between a first compressing element on the measuring-gas side and a second compressing element on the connector side, such that it tightly encloses the sensor element and hermetically seals the sensor element with respect to the molded housing.
摘要:
An electrochemical sensor for determining the oxygen content of gases of internal combustion engines includes a ceramic element that is inserted with a sealing ring into a housing. The sealing ring is built up from different metal layers. The arrangement of the metal layers proceeds from a metal support which is composed of a steel alloy. The sealing ring is covered on both sides with a roll-clad copper layer. A nickel layer can additionally be arranged beneath the copper layer.
摘要:
In an apparatus that ascertains a concentration of a component in a gas mixture, the apparatus includes: a gas measurement chamber, in which the concentration of the component is adjustable against an influence of an interface, acting across a diffusion barrier, with the concentration in the gas mixture, whereby the influence of the interface is compensated for by a controllable current of ions of the component by way of a solid electrolyte, which is charged with a controllable pumping voltage, serves as a pumping mechanism, and is located between the gas measurement chamber and the gas mixture, so that a parameter that characterizes a current constitutes a measurement for the concentration in the gas mixture, whereby the solid electrolyte is at least periodically charged with a specified constant pumping voltage as a function of at least one state parameter of the gas mixture.
摘要:
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.
摘要:
A sensor for determining the oxygen content in exhaust gases, particularly for lambda probes, is presented with catalytically active substances in the porous protective layer, which cover the electrode or electrodes exposed to the measuring gas, with discretely distributed platinum and homogenously distributed rhodium being used as catalytically active substances. The sensor in accordance with this invention guarantees excellent catalytic conversion of the exhaust gases and thus a control position of the sensor close to lambda=1.
摘要:
To provide for temperature measurement of a solid electrolyte polarographic gas composition sensor, an ac signal is superimposed from an ac voltage source (2) on the applied voltage from a voltage source (1) if the sensor is a polarographic sensor, the ac signal being separated from the output by a filter combination (6, 7), the dc output being evaluated as usual, and the ac output being rectified in a rectifier (9) to obtain a measure of the temperature since the ac resistance (R.sub.alt) is highly temperature dependent (see FIG. 3). The ac preferably is about 10% of the applied dc voltage, so that the voltage swing of the ac potential falls well within the linear range of output current with respect to voltage (see FIG. 2). The output from the ac channel (7, 9) to evaluate the temperature signal can be connected to a control loop circuit (10, 11), including a heater (11) to heat the sensor to maintain a uniform temperature thereof.