Abstract:
A temperature-dependent measuring resistor is connected to a reference resistor in series, wherein this series connection is flowed through by a constant impressed current. A connection point located between the two resistors is connected to the N-input of a first feedback differential amplifier, whose P-input is supplied with direct current voltage tapped from a voltage divider. During a temperature increase in the area of the measuring resistor, the potential increases at the output of the first differential amplifier, which delivers the constant impressed current and is connected to the measuring resistor, while the potential at the output of the differential amplifier falls when the temperature falls. The temperature-dependent voltage signal that is output at the differential amplifier is supplied in subtracting connection to the P-input of an after-connected second differential amplifier, whose output is connected to a measurement unit for measuring the voltage characteristic of the temperature. In a preferred embodiment, the measuring resistor made of platinum or of a platinum-based alloy is directly mounted on a substrate made of ceramic (Al2O3), which forms a thin-layer component. On the surface of the thin-layer component the reference resistor and the micro-module are mounted in addition. The temperature sensor has, because of an evaluation circuit constructed as a micro-module, a compact structural form and can be used up to a temperature of approx. 300° C.
Abstract:
For production of a high-temperature sensor, in which a platinum resistance film is applied on a metal-oxide substrate, in particular sapphire or a ceramic plate, and a ceramic intermediate layer is laid on the resistance film, a self-supporting cover, in particular a ceramic or glass-ceramic cover, is bonded on the ceramic intermediate layer or a glass ceramic is mounted on the intermediate layer over its entire surface. Advantageously, the glass ceramic is electrically conductive or an ion conductor above 750° C. and is laid on up to the cathode of the resistance film up to beyond the intermediate layer. In particular, the cover is bonded with a metal-doped glass ceramic, which is laid on the cathode of the resistance film up to beyond the intermediate layer. Preferably, the electrically insulating intermediate layer is coated with a glass ceramic or a glass ceramic doped with metal, which coating has a resistance of at most one megaohm per square at 850° C. or above.
Abstract:
A measurement device, particularly an anemometric measurement device, is provided for mounting in an exhaust-gas pipe, particularly an exhaust-gas recirculation pipe. The device includes a ceramic carrier embedded in an injection-molded housing made of plastic, with at least one film resistor mounted on the ceramic carrier on an end opposite the embedding. Electrical connections lead out from the film resistor to the embedded end of the ceramic carrier, and the electrical connections are passed through the injection molding, sealed and mounted within the injection-molded part. Additional components can be used for the sealing and mounting.
Abstract:
A temperature-dependent measuring resistance with rapid response time is at least partially arranged on an electrically insulating surface of a ceramic substrate, wherein a portion of the conductor path spans a recess situated in the substrate in a bridge-like manner, and the remaining portion of the conductor path in the edge area of the substrate adjacent to the recess is provided with connection contact fields. The conductor path comprises a platinum or gold layer, wherein the conductor path is partially provided with a cover layer of glass, and wherein the connection contact fields are exposed. In a further embodiment, the conductor path is arranged together with the connection contact fields either on a screen-printed glass membrane or on a thin film membrane applied in a PVD process, which covers the surface of the ceramic substrate and spans the recess. The cover layer is likewise selectively applied by screen printing in case there is a glass membrane. In the case of a thin film membrane, the cover layer is also applied selectively by a PVD process and can be the same material as the thin film membrane. The ceramic substrate preferably comprises aluminum oxide.
Abstract:
A sensor, particularly an impedance sensor, for example a soot sensor, is provided which has two mutually electrically insulated electrodes, wherein at least one external electrode is formed from a composite of metal and inorganic oxide as a film pattern having a film thickness of 0.5 to 20 μm. The trace width of the film pattern and the spacing between the traces is 5 to 70 μm and the border region around the conductor trace edge varies less than 10 μm. Both electrodes can be arranged adjacent to each other as a film pattern in a plane. Preferably, the sensor has a heater. For mass production, electrodes are produced as a film pattern having a film thickness of 0.5 to 20 μm on electrically insulating oxide bases and, following full-surface imprinting of a metal powder and oxide-containing paste, the electrodes are structured particularly accurately as traces from the printed film. In particular, the film thickness of the printed film is reduced.
Abstract:
A resistance thermometer is provided having a measuring resistor in a form of a 0.1 to 10 μm thick structured platinum layer applied to an electrically insulated surface of a substrate and an electrically insulating coating layer covering the platinum layer. The substrate or its surface contains zirconium dioxide, which is stabilized with oxides of a trivalent and a pentavalent metal. Preferably, the trivalent metal is yttrium and the pentavalent metal is tantalum or niobium. The characteristic curve of the measuring resistor preferably conforms to DIN-IEC 751. For mass production of resistance thermometers having high and reproducible measurement accuracy, a structured platinum layer having a thickness of 0.1 to 10 μm is applied to an electrically insulating substrate having a thermal expansion coefficient in the range of 8.5 to 10.5×10−6/° K and a roughness less than 1 μm, and the structured platinum layer is covered by an electrical insulator. The resistance thermometers allow precise temperature measurement between −200° C. and +850° C., preferably as a sensor in an exhaust gas treatment system. In a substance-sensitive sensor having a circuit path structure on a substrate, the circuit path structure has an epitaxially applied base layer, and a substance-sensitive metal layer attached to the epitaxially applied base layer.
Abstract:
A sensor, particularly an impedance sensor, for example a soot sensor, is provided which has two mutually electrically insulated electrodes, wherein at least one external electrode is formed from a composite of metal and inorganic oxide as a film pattern having a film thickness of 0.5 to 20 μm. The trace width of the film pattern and the spacing between the traces is 5 to 70 μm and the border region around the conductor trace edge varies less than 10 μm. Both electrodes can be arranged adjacent to each other as a film pattern in a plane. Preferably, the sensor has a heater. For mass production, electrodes are produced as a film pattern having a film thickness of 0.5 to 20 μm on electrically insulating oxide bases and, following full-surface imprinting of a metal powder and oxide-containing paste, the electrodes are structured particularly accurately as traces from the printed film. In particular, the film thickness of the printed film is reduced.
Abstract:
A resistance thermometer is provided having a measuring resistor in a form of a 0.1 to 10 μm thick structured platinum layer applied to an electrically insulated surface of a substrate and an electrically insulating coating layer covering the platinum layer. The substrate or its surface contains zirconium dioxide, which is stabilized with oxides of a trivalent and a pentavalent metal. Preferably, the trivalent metal is yttrium and the pentavalent metal is tantalum or niobium. The characteristic curve of the measuring resistor preferably conforms to DIN-IEC 751. For mass production of resistance thermometers having high and reproducible measurement accuracy, a structured platinum layer having a thickness of 0.1 to 10 μm is applied to an electrically insulating substrate having a thermal expansion coefficient in the range of 8.5 to 10.5×10−6/° K and a roughness less than 1 μm, and the structured platinum layer is covered by an electrical insulator. The resistance thermometers allow precise temperature measurement between −200° C. and +850° C., preferably as a sensor in an exhaust gas treatment system. In a substance-sensitive sensor having a circuit path structure on a substrate, the circuit path structure has an epitaxially applied base layer, and a substance-sensitive metal layer attached to the epitaxially applied base layer.
Abstract:
A flow sensor element and a method for self-cleaning of the flow sensor element are provided, in which a temperature-measuring element and a heating element are arranged on a carrier element, and these elements can form a multiple-part ceramic component. The temperature-measuring element has a platinum thin-film resistor on a ceramic substrate for the temperature measurement and is heated with an additional platinum thin-film resistor. A measurement device, in particular an anemometric measurement device of a flow sensor, contains film resistors mounted in at least one opening of a cover or a hollow body. Two of the film resistors have resistance values differing by one to three orders of magnitude. The anemometric measurement device has a temperature sensor and a heat output sensor set in a carrier element. The temperature sensor has a temperature-measuring resistor and a heat conductor, as platinum thin-film or thick-film resistors, on a ceramic substrate.
Abstract:
The present invention relates to soot sensors based on one-piece strip conductor structures, to methods for measuring soot, and to the use of heat conductor chips for soot measurement. For this purpose, the invention is based on the sensitivity of intensive variables, especially substance-specific variables.According to the invention, an electric soot sensor is provided, in which at least one chip is provided with at least one one-piece strip conductor having, in particular, two terminal panels, and the soot sensor has a soot determination facility that is adapted to determine an intensive or specific change of a surface.The inventive method is characterized by soot deposits causing a change of an intensive variable, especially of a thermospecific or electrical parameter of a chip, and by determination of said variable.