摘要:
To compensate for temperature-dependent shift on the operating characteristics of an oxygen ion conductive sensor which tends to shift the operating characteristics towards the "lean" range (.lambda.>1) at low temperature, and towards the "rich" range (.lambda.
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.
摘要:
To permit use of less expensive iron powder material and manufacture of more complex shapes, a mixture of iron powder, of an approximate grain size of between 30 to 450 .mu.m, and containing preferably 5 to 50% of carbonyl iron powder or from 5 to 50%, by weight, of soft ferrite powder of a grain size of from 10 to 200 .mu.m, and a thermosetting resin, in which the thermosetting resin is about 50% by volume of the overall mixture, is filled into a die. Pressure is built up in the die, which is heated, permitting excess binder to escape during the build-up phase thereof, the pressure then being held so that the resin can set in the heated die. The pressures needed are substantially less than heretofore required, in the order of from between 500 to 5000 bar.
摘要:
A sensor element which is used for determining a property of a measuring gas, e.g., for determining the concentration of a gas component in the measuring gas, has at least one electrode applied to one solid electrolyte, the electrode being in contact with the measuring gas via a diffusion path in which a diffusion barrier is situated. A means is provided in the region of the side of the diffusion barrier facing away from the electrode, the means reducing the diffusion cross section in the region of the side of the diffusion barrier facing away from the electrode.
摘要:
A sensor element is used to detect a physical property of a measuring gas, preferably to determine the oxygen content or the temperature of an exhaust gas of an internal combustion engine. The sensor element contains a first solid electrolyte layer and a second solid electrolyte layer. A first printed conductor and a second printed conductor are provided on opposite sides of the first solid electrolyte layer, the first printed conductor including a first electrode and a feed line to the first electrode, and the second printed conductor including a second electrode and a feed line to the second electrode. A third printed conductor, which includes a third electrode and a feed line to the third electrode, is provided on the second solid electrolyte layer. The second printed conductor is positioned between the third electrode and the first printed conductor.
摘要:
A plate-shaped sensor element is proposed, in particular for determining the oxygen level in exhaust gases of internal combustion engines. The sensor element has at least one measuring cell with an oxygen-ion-conducting solid electrolyte and a heating element, the measuring cell and the heating element being connected with an electrical insulation layer. The material of the insulation layer is made of at least one crystalline, non-metallic material and at least one glass-forming material, a glazing filled with the crystalline, non-metallic material being formed when the sensor element is sintered.
摘要:
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.