EP1127273A1 - Sensor arrangement for detecting the physical properties of liquids - Google Patents
Sensor arrangement for detecting the physical properties of liquidsInfo
- Publication number
- EP1127273A1 EP1127273A1 EP99957946A EP99957946A EP1127273A1 EP 1127273 A1 EP1127273 A1 EP 1127273A1 EP 99957946 A EP99957946 A EP 99957946A EP 99957946 A EP99957946 A EP 99957946A EP 1127273 A1 EP1127273 A1 EP 1127273A1
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- Prior art keywords
- sensor arrangement
- arrangement according
- substrate
- measurement
- measuring
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/02—Analysing fluids
- G01N29/036—Analysing fluids by measuring frequency or resonance of acoustic waves
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
- G01N11/10—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material
- G01N11/16—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by moving a body within the material by measuring damping effect upon oscillatory body
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/22—Measuring resistance of fluids
Definitions
- the invention relates to a sensor arrangement for determining physical properties of liquids according to the preamble of the main claim.
- SAW Surface Acoustic Wave
- An important area here is the measurement of electrical quantities, such as the dielectric constant and / or the conductivity, the measurement of mechanical quantities, such as the density and / or the viscosity.
- the known sensor arrangement is based on a measurement principle which is described, for example, in the article "A study of love-wave acoustic sensors", J.Du, GL Harding, PROgilvy and M.Lake in the specialist journal Sen- sors and Actuators A56 (1996), pages 211 to 219.
- a sensor is implemented that works with horizontally polarized acoustic shear waves, so-called leakage waves or surface skimming bulk waves (SSBW waves) or love waves.
- SSBW waves surface skimming bulk waves
- interdigital transducers which are also known per se from the prior art mentioned above, so that the desired sensor signal can be obtained from the propagation behavior on a propagation or measurement path.
- the sensor arrangement is used to determine the quality of engine or lubricating oils in a motor vehicle or comparable machines, it is often necessary to obtain a large number of measurement variables in order to evaluate them as input variables for corresponding control units. Above all, the viscosity, the temperature, the electrical conductivity and the dielectric constant of the oil are important for a useful statement, e.g. to monitor the oil change intervals.
- the sensor arrangement mentioned at the outset for determining physical properties of liquids is advantageously further developed according to the invention with the characterizing features of the main claim.
- a compact sensor arrangement is advantageously created, with which an integration of different individual measurement sensors on a substrate plate is made possible with low-cost production.
- the electro-acoustic transducers which generate and detect the surface acoustic waves with predetermined wave modes are advantageously arranged together with further measuring arrangements.
- a corresponding measured value is determined from the propagation behavior of the acoustic waves along a propagation path in the manner known per se.
- the basic sensor element is, for example, a substrate made of certain quartz, lithium tantalate and lithium niobate sections which are particularly suitable for the acoustic shear modes described at the beginning.
- a temperature-dependent resistor is advantageously attached adjacent to the substrate as a measuring arrangement for temperature measurement.
- the conductor track structure on the substrate is produced from a metallization layer, advantageously from platinum, whereby both the temperature-dependent resistance and the transmission and reception conductor track structures of the electro-acoustic transducer can be produced from this platinum layer, so that only a single metallization layer on the substrate is necessary is. Platinum is extremely chemically resistant, so that cover layers can be dispensed with under certain circumstances.
- a dielectric layer applied above the metallization layer on the substrate can, however, also be arranged as an acoustic waveguide layer for the electro-acoustic transducers in addition to the chemical passivation. It is also possible to use titanium or silicon or other intermediate layers as an adhesive layer between the substrate and the electro-acoustic wall learners as well as between the electro-acoustic transducers and other layers above.
- an arrangement for electrical conductivity measurement can advantageously also be produced from the metallization layer by means of uncovered electrodes.
- the conductivity measurement is carried out in a simple manner with a direct current or an alternating current which flows through the liquid.
- an arrangement for measuring the dielectric constant can advantageously be created from the same metallization layer by means of a capacitor structure.
- the capacitor structure can be in the form of an interdigital capacitor and, if appropriate, can be covered by an additional insulating layer; However, it is also possible to use it uncovered for better coupling to the liquid to be measured, wherein the chemical resistance of the metallization layer can be exploited.
- all measuring arrangements for determining the individual physical quantities can be contacted individually in a simple manner, and thus all four measuring methods can be carried out on a corresponding evaluation electronics for sequential measurement with a single substrate, which can be used particularly for construction forms which are favorable for production. Furthermore, the good heat coupling on the substrate is also advantageous, since the temperature of the various measuring sensors is available with particularly small deviations during signal evaluation, so that very precise compensation methods can be used.
- the schematic view according to the single figure shows the main component of the proposed sensor arrangement, namely a substrate plate 1 polished on one side from a piezoelectric material, in which horizontally polarized acoustic shear modes can be excited by an interdigital transducer 3 that can be contacted via electrical connections 2 and in an interdigital transducer 4 as an electro -acoustic transducers are detectable.
- the measuring arrangement described above with the electro-acoustic transducers for measuring the viscosity of a measuring liquid via the propagation of a surface wave and the measuring arrangements described below are structured from a metallization layer, preferably from platinum, and optionally adhesive layers.
- a dielectric layer (not shown here) can also be arranged above the electro-acoustic transducers 3 and 4 as an acoustic waveguide layer, which also enables chemical passivation.
- electrodes 5 for conductivity measurement are present on the substrate 1 and are supplied with a direct or alternating current.
- conductivity measurement could also be dispensed with in many application stalls.
- the temperature measurement is carried out here via a resistance meander 6, which is likewise structured from the metallization layer.
- the arrangement of the resistance meander 6 can also lie outside the propagation distance between the transducers 3 and 4, in a modification of the shape shown.
- a capacitor structure 7 which, for better coupling to the liquid to be measured, is either uncovered or provided with a cover layer 8 shown here in broken lines in order to improve the chemical resistance.
- the measurement of the dielectric constant and the conductivity can possibly also be carried out with the electro-acoustic transducers for determining the viscosity of the liquid a different excitation frequency than the frequency required to generate the surface wave is selected.
- the measuring liquid e.g.
- the engine oil of a motor vehicle flows past the substrate surface and possibly the cover layer to determine the physical properties, and the measurement signals obtained are taken at the contact points and an evaluation device (not shown here) for generating the necessary control and / or display signals, e.g. for the quality of the engine oil.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Acoustics & Sound (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
The invention relates to sensor arrangement for detecting the physical parameters of liquids. Said arrangement comprises electroacoustic converters (3, 4) which produce and detect surface acoustic waves having predetermined wave modes. Based on the expansion behavior of these waves a measure for the physical properties of the liquid, especially for its viscosity, can be detected. The sensor arrangement is located on a substrate (1) on which conductor track structures are arranged in such a way that in addition to the electroacoustic converters (3, 4) for measuring viscosity an arrangement for measuring the electric conductivity (5), an arrangement for measuring the relative permittivity (7) and an arrangement for measuring the temperature (6) is configured.
Description
Sensoranordnung zur Ermittlung physikalischer Eigenschaften von FlüssigkeitenSensor arrangement for determining physical properties of liquids
Stand der TechnikState of the art
Die Erfindung betrifft eine Sensoranordnung zur Ermittlung physikalischer Eigenschaften von Flüssigkeiten nach dem Oberbegriff des Hauptanspruchs.The invention relates to a sensor arrangement for determining physical properties of liquids according to the preamble of the main claim.
Es werden beispielsweise mikroakustische Sensoranordnun- gen mit sogenannten akustischen SAW- oder Oberflächenwel- lenbauelementen (SAW = Surface Acoustic Wave) als Sensoren für verschiedenste physikalische Größen in Flüssigkeiten angewandt. Einen wichtigen Bereich bildet hierbei die Messung elektrischer Größen, wie die Dielektrizitätskonstante und/oder die Leitfähigkeit, die Messung mechanischer Größen, wie z.B. die Dichte und/oder die Viskosität.For example, microacoustic sensor arrangements with so-called acoustic SAW or surface wave components (SAW = Surface Acoustic Wave) are used as sensors for various physical quantities in liquids. An important area here is the measurement of electrical quantities, such as the dielectric constant and / or the conductivity, the measurement of mechanical quantities, such as the density and / or the viscosity.
Bei der bekannten Sensoranordnung wird von einem Mes- sprinzip ausgegangen, das beispielsweise in dem Aufsatz „A study of Love-wave acoustic sensors", J.Du, G.L. Hard- ling, P.R.Ogilvy und M.Lake in der Fachzeitschrift Sen-
sors and Actuators A56(1996), Seiten 211 bis 219 beschrieben ist. Mit dem hier beschriebenen Messaufbau ist ein Sensor realisiert, bei dem mit horizontal polarisierten akustischen Scherwellen gearbeitet wird, sog. Leckwellen bzw. Surface Skimming Bulk Wave (SSBW-Wellen) oder Love-Wellen. Diese akustischen Wellenmoden werden mit sogenannten, für sich auch aus dem zuvor erwähnten Stand der Technik bekannten, Interdigitaltransducern erzeugt und auch detektiert, so dass aus dem Ausbreitungsverhalten auf einer Ausbreitungs- oder Messstrecke das gewünschte Sensorsignal gewonnen werden kann.The known sensor arrangement is based on a measurement principle which is described, for example, in the article "A study of love-wave acoustic sensors", J.Du, GL Harding, PROgilvy and M.Lake in the specialist journal Sen- sors and Actuators A56 (1996), pages 211 to 219. With the measurement setup described here, a sensor is implemented that works with horizontally polarized acoustic shear waves, so-called leakage waves or surface skimming bulk waves (SSBW waves) or love waves. These acoustic wave modes are generated and also detected with so-called interdigital transducers, which are also known per se from the prior art mentioned above, so that the desired sensor signal can be obtained from the propagation behavior on a propagation or measurement path.
Insbesondere bei einer Anwendung der Sensoranordnung zur Bestimmung der Qualität von Motor- oder Schmierölen in einem Kraftfahrzeug oder vergleichbaren Maschinen ist es oft notwendig eine Vielzahl von Messgrößen zu gewinnen, um diese als Eingangsgrößen für entsprechende Steuergeräte auszuwerten. Hierbei sind vor allem die Viskosität, die Temperatur, die elektrische Leitfähigkeit und die Dielektrizitätskonstante des Öls von Bedeutung um eine brauchbare Aussage, z.B. zur Überwachung der Ölwechselintervalle, zu erhalten.Particularly when the sensor arrangement is used to determine the quality of engine or lubricating oils in a motor vehicle or comparable machines, it is often necessary to obtain a large number of measurement variables in order to evaluate them as input variables for corresponding control units. Above all, the viscosity, the temperature, the electrical conductivity and the dielectric constant of the oil are important for a useful statement, e.g. to monitor the oil change intervals.
Vorteile der ErfindungAdvantages of the invention
Die eingangs erwähnte Sensoranordnung zur Ermittlung von physikalischen Eigenschaften von Flüssigkeiten ist nach der Erfindung mit den kennzeichnenden Merkmalen des Hauptanspruchs in vorteilhafter Weise weitergebildet. Gemäß der Erfindung wird in vorteilhafter Weise eine kompakte Sensoranordnung geschaffen, mit der eine Integration verschiedener einzelner Messwertaufnehmer auf einem Substratplättchen bei kostengünstiger Herstellung ermöglicht ist.
Beim der erfindungsgemäßen Sensoranordnung sind in vorteilhafter Weise die elektro-akustischen Wandler, die die akustischen Oberflächenwellen mit vorgegebenen Wellenmoden erzeugen und detektieren, zusammen mit weiteren Messanordnungen angeordnet. Zur Messung der Viskosität der Flüssigkeit wird hier aus dem Ausbreitungsverhalten der akustischen Wellen entlang einer Ausbreitungsstrecke ein entsprechender Messwert in der für sich gesehen bekannten Weise ermittelt. Das Sensorgrundelement ist beispielsweise ein Substrat aus bestimmten Quarz-, Lithiumtantalat- und Lithiumniobatschnitten, die für die eingangs beschriebenen akustischen Schermoden besonders geeignet sind.The sensor arrangement mentioned at the outset for determining physical properties of liquids is advantageously further developed according to the invention with the characterizing features of the main claim. According to the invention, a compact sensor arrangement is advantageously created, with which an integration of different individual measurement sensors on a substrate plate is made possible with low-cost production. In the sensor arrangement according to the invention, the electro-acoustic transducers which generate and detect the surface acoustic waves with predetermined wave modes are advantageously arranged together with further measuring arrangements. To measure the viscosity of the liquid, a corresponding measured value is determined from the propagation behavior of the acoustic waves along a propagation path in the manner known per se. The basic sensor element is, for example, a substrate made of certain quartz, lithium tantalate and lithium niobate sections which are particularly suitable for the acoustic shear modes described at the beginning.
Da die Viskosität der Flüssigkeit in der Regel stark temperaturabhängig ist, wird nach der Erfindung in vorteilhafter Weise auf dem Substrat benachbart ein temperaturabhängiger Widerstand als Messanordnung zur Temperaturmessung angebracht. Die Leiterbahnstruktur auf dem Substrat ist aus einer Metallisierungsschicht hergestellt, vorteilhafter Weise aus Platin, wobei sowohl der temperaturabhängige Widerstand als auch die Sende- und Empfangsleiterbahnstrukturen des elektro-akustischen Wandlers aus dieser Platinschicht hergestellt werden kann, so dass nur eine einzige Metallisierungsschicht auf dem Substrat notwendig ist. Platin ist hierbei chemisch außerordentlich resistent, so dass auf Abdeckschichten unter Umständen verzichtet werden kann.Since the viscosity of the liquid is generally highly temperature-dependent, according to the invention, a temperature-dependent resistor is advantageously attached adjacent to the substrate as a measuring arrangement for temperature measurement. The conductor track structure on the substrate is produced from a metallization layer, advantageously from platinum, whereby both the temperature-dependent resistance and the transmission and reception conductor track structures of the electro-acoustic transducer can be produced from this platinum layer, so that only a single metallization layer on the substrate is necessary is. Platinum is extremely chemically resistant, so that cover layers can be dispensed with under certain circumstances.
Eine oberhalb der Metallisierungsschicht auf dem Substrat aufgebrachte dielektrische Schicht kann jedoch auch als akustische Wellenleiterschicht für die elektro- akustischen Wandler zusätzlich zur chemischen Passivie- rung angeordnet werden. Es ist auch möglich Titan oder Silizium oder andere Zwischenschichten als Haftschicht zwischen dem Substrat und den elektro-akustischen Wand-
lern sowie zwischen den elektro-akustischen Wandlern und weiteren darüberliegenden Schichten vorzusehen.A dielectric layer applied above the metallization layer on the substrate can, however, also be arranged as an acoustic waveguide layer for the electro-acoustic transducers in addition to the chemical passivation. It is also possible to use titanium or silicon or other intermediate layers as an adhesive layer between the substrate and the electro-acoustic wall learners as well as between the electro-acoustic transducers and other layers above.
Neben den elektro-akustischen Wandlern und dem temperaturabhängigen Widerstand kann in vorteilhafter Weise auch mittels unabgedeckter Elektroden eine Anordnung zur elektrischen Leitfähigkeitsmessung aus der Metallisierungsschicht hergestellt werden. Die Leitfähigkeitsmessung erfolgt auf einfache Weise mit einem Gleichstrom oder einem Wechselstrom, der die Flüssigkeit durchströmt.In addition to the electro-acoustic transducers and the temperature-dependent resistance, an arrangement for electrical conductivity measurement can advantageously also be produced from the metallization layer by means of uncovered electrodes. The conductivity measurement is carried out in a simple manner with a direct current or an alternating current which flows through the liquid.
Weiterhin kann in vorteilhafter Weise mittels einer Kondensatorstruktur aus derselben Metallisierungsschicht eine Anordnung zur Messung der Dielektrizitätskonstante geschaffen werden. Die Kondensatorstruktur kann ebenso wie der elektro-akustische Wandler die Form eines Interdigi- talkondensators haben und gegebenenfalls durch eine zusätzliche Isolierschicht abgedeckt werden; es ist aber auch möglich zur besseren Ankopplung an die zu messende Flüssigkeit diesen unabgedeckt einzusetzen, wobei die chemische Resistenz der Metallisierungsschicht ausgenutzt werden kann.Furthermore, an arrangement for measuring the dielectric constant can advantageously be created from the same metallization layer by means of a capacitor structure. Like the electro-acoustic transducer, the capacitor structure can be in the form of an interdigital capacitor and, if appropriate, can be covered by an additional insulating layer; However, it is also possible to use it uncovered for better coupling to the liquid to be measured, wherein the chemical resistance of the metallization layer can be exploited.
Auf einfache Weise sind bei der erfindungsgemäßen Anordnung alle Meεsanordnungen zur Ermittlung der einzelnen physikalischen Größen einzeln kontaktierbar und somit sind alle vier Messverfahren an einer entsprechenden Auswerteelektronik zur sequentiellen Messung mit einem einzigen Substrat durchführbar, was besonders für fertigungsgünstige Konstruktionsformen ausgenutzt werden kann. Weiterhin ist auch die gute Wärmekopplung auf dem Substrat vorteilhaft, da bei der Signalauswertung dadurch mit besonders geringen Abweichungen die Temperatur der verschiedenen Messwertaufnehmer zur Verfügung steht, so dass sehr genaue Kompensationsverfahren angewandt werden können .
Diese und weitere Merkmale von bevorzugten Weiterbildungen der Erfindung gehen außer aus den Ansprüchen auch aus der Beschreibung und den Zeichnungen hervor, wobei die einzelnen Merkmale jeweils für sich allein oder zu mehreren in Form von Unterkombinationen bei der Ausführungs- form der Erfindung und auf anderen Gebieten verwirklicht sein und vorteilhafte sowie für sich schutzfähige Ausführungen darstellen können, für die hier Schutz beansprucht wird.In the arrangement according to the invention, all measuring arrangements for determining the individual physical quantities can be contacted individually in a simple manner, and thus all four measuring methods can be carried out on a corresponding evaluation electronics for sequential measurement with a single substrate, which can be used particularly for construction forms which are favorable for production. Furthermore, the good heat coupling on the substrate is also advantageous, since the temperature of the various measuring sensors is available with particularly small deviations during signal evaluation, so that very precise compensation methods can be used. These and other features of preferred developments of the invention are evident from the claims and also from the description and the drawings, the individual features being realized individually or in groups in the form of subcombinations in the embodiment of the invention and in other fields be and can represent advantageous and protectable designs for which protection is claimed here.
Zeichnungdrawing
Ein Ausführungsbeispiel einer erfindungsgemäßen Sensoranordnung wird anhand der einzigen Figur der Zeichnung erläutert, die eine schematische Draufsicht auf ein Substrat mit einzelnen Messwerterfassungsanordnungen zeigt.An embodiment of a sensor arrangement according to the invention is explained with reference to the single figure of the drawing, which shows a schematic plan view of a substrate with individual measurement value acquisition arrangements.
Beschreibung des AusführungsbeispielsDescription of the embodiment
Die schematische Ansicht nach der einzigen Figur zeigt den Hauptbestandteil der vorgeschlagenen Sensoranordnung, nämlich ein einseitig poliertes Substratplättchen 1 aus einem piezoelektrischen Werkstoff, in dem horizontal polarisierte akustische Schermoden von einem, über elektrische Anschlüsse 2 kontaktierbaren Interdigitaltransducer 3. anregbar und in einem Interdigitaltransducer 4 als elektro-akustische Wandler detektierbar sind. Die Funktionsweise dieser Anordnung, beispielsweise zur Bestimmung der Viskosität einer Flüssigkeit, ist beispielsweise in dem eingangs zitierten Stand der Technik „ A study of Love-wave acoustic Sensors", J.Du, G.L.Hardling, P.R. Ogilvy und M.Lake in der Fachzeitschrift Sensors and Ac- tuators A5β(1996), Seiten 211 bis 219 beschrieben.
Als Substratwerkstoffe für das Substratplattchen 1 sind Y-rotierte Quarzschnitte, einige Lithiumniobat- und Lithiumtantalatschnitte sowie entsprechend gepolte piezoelektrische Keramiken geeignet. Die zuvor beschriebene Messanordnung mit den elektro-akustischen Wandlern zur Messung der Viskosität einer Messflüssigkeit über die Ausbreitung einer Oberflächenwelle und die nachfolgend beschriebenen Messanordnungen sind aus einer Metallisierungsschicht, vorzugsweise aus Platin, und gegebenenfalls Haftschichten strukturiert. Über den elektro-akustischen Wandlern 3 und 4 kann dabei auch eine hier nicht ersichtliche dielektrische Schicht als akustische Wellenleiterschicht angeordnet werden, die auch eine chemische Passi- vierung ermöglicht.The schematic view according to the single figure shows the main component of the proposed sensor arrangement, namely a substrate plate 1 polished on one side from a piezoelectric material, in which horizontally polarized acoustic shear modes can be excited by an interdigital transducer 3 that can be contacted via electrical connections 2 and in an interdigital transducer 4 as an electro -acoustic transducers are detectable. The mode of operation of this arrangement, for example for determining the viscosity of a liquid, is described, for example, in the prior art cited at the outset, “A study of love-wave acoustic sensors”, J.Du, GLHardling, PR Ogilvy and M.Lake in the trade journal Sensors and Actuators A5β (1996), pages 211 to 219. Y-rotated quartz cuts, some lithium niobate and lithium tantalate cuts and correspondingly polarized piezoelectric ceramics are suitable as substrate materials for the substrate platelet 1. The measuring arrangement described above with the electro-acoustic transducers for measuring the viscosity of a measuring liquid via the propagation of a surface wave and the measuring arrangements described below are structured from a metallization layer, preferably from platinum, and optionally adhesive layers. A dielectric layer (not shown here) can also be arranged above the electro-acoustic transducers 3 and 4 as an acoustic waveguide layer, which also enables chemical passivation.
Weiterhin sind auf dem Substrat 1 Elektroden 5 zur Leit- fähigkeitsmessung vorhanden, die mit einem Gleich- oder Wechselstrom beaufschlagt werden. Auf eine Leitfähigkeitsmessung könnte jedoch auch in vielen Anwendungstallen verzichtet werden. Die Temperaturmessung wird hier über ein ebenfalls aus der Metallisierungsschicht strukturierten Widerstandsmäander 6 durchgeführt. Die Anordnung des Widerstandsmäanders 6 kann dabei auch, in Abwandlung der dargestellten Form außerhalb der Ausbrei- tungsstrecke zwischen den Wandlern 3 und 4 liegen.Furthermore, electrodes 5 for conductivity measurement are present on the substrate 1 and are supplied with a direct or alternating current. However, conductivity measurement could also be dispensed with in many application stalls. The temperature measurement is carried out here via a resistance meander 6, which is likewise structured from the metallization layer. The arrangement of the resistance meander 6 can also lie outside the propagation distance between the transducers 3 and 4, in a modification of the shape shown.
Für die Messung der Dielektrizitätskonstante ist eine Kondensatorstruktur 7 vorhanden, die zur besseren Ankopp- lung an die zu messende Flüssigkeit entweder unabgedeckt oder mit einer hier gestrichelt gezeichneten Abdeck- schicht 8 zur Verbesserung der chemischen Resistenz versehen ist. Die Messung der Dielektrizitätskonstante und der Leitfähigkeit kann eventuell auch mit den elektro- akustischen Wandlern zur Bestimmung der Viskosität der Flüssigkeit vorgenommen werden, wobei hierzu lediglich
eine andere Anregungsfrequenz als die zur Erzeugung der Oberflächenwelle notwendige Frequenz gewählt wird.For the measurement of the dielectric constant there is a capacitor structure 7 which, for better coupling to the liquid to be measured, is either uncovered or provided with a cover layer 8 shown here in broken lines in order to improve the chemical resistance. The measurement of the dielectric constant and the conductivity can possibly also be carried out with the electro-acoustic transducers for determining the viscosity of the liquid a different excitation frequency than the frequency required to generate the surface wave is selected.
Die Messflüssigkeit , z.B. das Motoröl eines Kraftfahrzeuges, fließt zur Bestimmung der physikalischen Eigenschaften an der Substratoberfläche und gegebenenfalls an der Abdeckschicht vorbei und die gewonnenen Messsignale werden an den Kontaktstellen abgenommen und einer hier nicht dargestellten Auswerteeinrichtung zur Erzeugung der notwendigen Steuer- und/oder Anzeigesignale, z.B. für die Qualität des Motoröls, zugeführt.
The measuring liquid, e.g. The engine oil of a motor vehicle flows past the substrate surface and possibly the cover layer to determine the physical properties, and the measurement signals obtained are taken at the contact points and an evaluation device (not shown here) for generating the necessary control and / or display signals, e.g. for the quality of the engine oil.
Claims
Patentansprücheclaims
1) Sensoranordnung zur Ermittlung physikalischer Größen von Flüssigkeiten, mit1) Sensor arrangement for determining physical quantities of liquids, with
- mit elektro-akustischen Wandlern (3,4), die akustische Oberflächenwellen mit vorgegebenen Wellenmoden erzeugen und detektieren, wobei aus deren Ausbreitungsverhalten entlang einer Ausbreitungsstrecke ein Maß für physikalischen Eigenschaften der Flüssigkeit, insbesondere unter anderem der Viskosität der Flüssigkeit, ermittelbar ist, dadurch gekennzeichnet, dass- With electro-acoustic transducers (3, 4) which generate and detect surface acoustic waves with predetermined wave modes, wherein a measure of the physical properties of the liquid, in particular the viscosity of the liquid, among other things, can be determined from their propagation behavior along a propagation distance that
- die Sensoranordnung auf einem Substrat (1) angebracht ist, auf dem Leiterbahnstrukturen derart angeordnet sind, dass neben der Viskosität auch die Temperatur und mindestens auch die Dielektrizitätskonstante der Flüssigkeit ermittelbar ist.- The sensor arrangement is mounted on a substrate (1) on which conductor track structures are arranged such that in addition to the viscosity, the temperature and at least also the dielectric constant of the liquid can be determined.
2) Sensoranordnung nach Anspruch 1, dadurch gekennzeichnet, dass2) Sensor arrangement according to claim 1, characterized in that
- neben den elektro-akustischen Wandlern (3,4) mittels einer Kondensatorstruktur (7) eine Anordnung zur Messung der Dielektrizitätskonstante und mittels eines tempera-
turabhängigen Widerstandes (6) eine Anordnung zur Temperaturmessung gebildet ist .- In addition to the electro-acoustic transducers (3, 4), an arrangement for measuring the dielectric constant and by means of a temperature an arrangement for temperature measurement is formed.
3) Sensoranordnung nach Anspruch 1, dadurch gekennzeichnet, dass3) Sensor arrangement according to claim 1, characterized in that
- die elektro-akustischen Wandlern (3,4) die Kondensatorstruktur (7) zur Messung der Dielektrizitätskonstante bilden, wobei die Messung bei einer von der Anregungsfrequenz der Oberflächenwellen abweichenden Frequenz erfolgt, und mittels eines temperaturabhängigen Widerstandes (6) eine Anordnung zur Temperaturmessung gebildet ist .- The electro-acoustic transducers (3, 4) form the capacitor structure (7) for measuring the dielectric constant, the measurement taking place at a frequency deviating from the excitation frequency of the surface waves, and an arrangement for temperature measurement being formed by means of a temperature-dependent resistor (6) .
4) Sensoranordnung nach Anspruch 2 oder 3, dadurch gekennzeichnet, dass4) Sensor arrangement according to claim 2 or 3, characterized in that
- mittels unabgedeckter Elektroden (5) eine Anordnung zur elektrischen Leitfähigkeitsmessung angeordnet ist.- An arrangement for electrical conductivity measurement is arranged by means of uncovered electrodes (5).
5) Sensoranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass5) Sensor arrangement according to one of the preceding claims, characterized in that
- die Leiterbahnstruktur aus einer Metallisierungsschicht auf dem Substrat (1) herstellbar ist.- The conductor track structure can be produced from a metallization layer on the substrate (1).
6 ) Sensoranordnung nach Anspruch 5, dadurch gekennzeichnet, dass6) Sensor arrangement according to claim 5, characterized in that
- die Metallisierungsschicht aus Platin ist. und auf einer Haftschicht angeordnet ist.
7) Sensoranordnung nach Anspruch 5, dadurch gekennzeichnet, dass- The metallization layer is made of platinum. and is arranged on an adhesive layer. 7) Sensor arrangement according to claim 5, characterized in that
- die Metallisierungsschicht auf einer Haftschicht angeordnet ist .- The metallization layer is arranged on an adhesive layer.
8) Sensoranordnung nach Anspruch 5 oder 6, dadurch gekennzeichnet, dass8) Sensor arrangement according to claim 5 or 6, characterized in that
- oberhalb der Metallisierungsschicht auf dem Substrat (1) eine dielektrische Schicht als akustische Wellenleiterschicht angeordnet ist.- A dielectric layer is arranged as an acoustic waveguide layer above the metallization layer on the substrate (1).
9) Sensoranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass9) Sensor arrangement according to one of the preceding claims, characterized in that
- alle Anordnung zur Ermittlung der einzelnen physikalischen Größen einzeln kontaktierbar und an eine Auswerteelektronik zur sequentiellen Messung anschließbar sind.- All arrangements for determining the individual physical quantities can be contacted individually and connected to an evaluation electronics for sequential measurement.
10) Sensoranordnung nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass10) Sensor arrangement according to one of the preceding claims, characterized in that
- die Sensoranordnung in einem Kraftfahrzeug zur Bestimmung der Qualität des Motoröls eingesetzt wird, wobei das Substrat (1) direkt in das zu messende Öl eintauchbar ist .
- The sensor arrangement is used in a motor vehicle to determine the quality of the engine oil, the substrate (1) being immersed directly in the oil to be measured.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19850799A DE19850799A1 (en) | 1998-11-04 | 1998-11-04 | Sensor arrangement for determining physical properties of liquids |
| DE19850799 | 1998-11-04 | ||
| PCT/DE1999/003458 WO2000026661A1 (en) | 1998-11-04 | 1999-10-28 | Sensor arrangement for detecting the physical properties of liquids |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1127273A1 true EP1127273A1 (en) | 2001-08-29 |
Family
ID=7886644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP99957946A Withdrawn EP1127273A1 (en) | 1998-11-04 | 1999-10-28 | Sensor arrangement for detecting the physical properties of liquids |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP1127273A1 (en) |
| JP (1) | JP2003502617A (en) |
| KR (1) | KR20010090813A (en) |
| AU (1) | AU749057B2 (en) |
| DE (1) | DE19850799A1 (en) |
| WO (1) | WO2000026661A1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10152777A1 (en) * | 2001-10-29 | 2003-05-15 | Hydac Electronic Gmbh | Device and method for determining the quality of a medium, in particular a lubricant and / or coolant |
| AU2003241851A1 (en) * | 2002-06-08 | 2003-12-22 | Lg Innotek Co., Ltd | Saw sensor device using slit acoustic wave and method thereof |
| DE102004049580A1 (en) * | 2004-10-12 | 2006-04-13 | Robert Bosch Gmbh | Method for detecting state parameters of a liquid |
| DE102006015111A1 (en) * | 2006-03-31 | 2007-10-04 | Schaeffler Kg | Rotatable, swiveling or axial ball and roller bearing for aging process, has lubricating grease-sensor provided with piezo-component utilized as measuring equipment, where sensor and/or piezo-component are designed in lamellar manner |
| DE102009055738A1 (en) * | 2009-11-26 | 2011-06-09 | Continental Automotive Gmbh | Method for determining the state of a reducing agent in a reducing agent tank |
| US9151736B2 (en) * | 2009-12-21 | 2015-10-06 | Wema Systems As | Quality sensor apparatus |
| GB2476317B (en) * | 2009-12-21 | 2014-02-12 | Wema System As | Quality sensor apparatus |
| FR2962224B1 (en) | 2010-07-02 | 2013-05-10 | Sartorius Stedim Biotech Sa | SENSOR DEVICE OF A PARAMETER RELATED TO AN ELECTRIC PHENOMENON OF A BIOPHARMACEUTICAL CONTENT AND A BIOPHARMACEUTICAL CONTAINER HAVING SUCH A SENSOR DEVICE. |
| DE102013009370A1 (en) | 2013-06-05 | 2014-12-11 | Hochschule Karlsruhe | Device for measuring fluid properties and their use |
| EP3156620B1 (en) | 2015-10-13 | 2018-09-12 | Plastic Omnium Advanced Innovation and Research | Method of determining the concentration of a chemical agent in a solution based on a pressure wave velocity and a system therefor |
| DE102015016887A1 (en) * | 2015-12-22 | 2017-06-22 | Dürr Somac GmbH | Device for measuring the water content in brake fluids |
| CN109844469B (en) * | 2016-09-13 | 2022-05-13 | 帕塞罗股份有限公司 | Method and device for determining and/or monitoring the breakdown voltage of transformer oil |
| NO343381B1 (en) | 2017-10-05 | 2019-02-18 | Sentec As | Level sensor assembly |
| DE102018210387B4 (en) * | 2018-06-26 | 2023-03-23 | Robert Bosch Gmbh | Sensor device and method for detecting gases |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5130257A (en) * | 1988-09-29 | 1992-07-14 | Hewlett-Packard Company | Chemical sensor utilizing a surface transverse wave device |
| US5741961A (en) * | 1993-08-18 | 1998-04-21 | Sandia Corporation | Quartz resonator fluid density and viscosity monitor |
| DE19710358C2 (en) * | 1997-03-13 | 2000-11-30 | Bosch Gmbh Robert | Microstructured sensor |
-
1998
- 1998-11-04 DE DE19850799A patent/DE19850799A1/en not_active Withdrawn
-
1999
- 1999-10-28 KR KR1020017005559A patent/KR20010090813A/en not_active Application Discontinuation
- 1999-10-28 EP EP99957946A patent/EP1127273A1/en not_active Withdrawn
- 1999-10-28 AU AU15490/00A patent/AU749057B2/en not_active Ceased
- 1999-10-28 JP JP2000579991A patent/JP2003502617A/en active Pending
- 1999-10-28 WO PCT/DE1999/003458 patent/WO2000026661A1/en not_active Application Discontinuation
Non-Patent Citations (1)
| Title |
|---|
| See references of WO0026661A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| DE19850799A1 (en) | 2000-05-11 |
| WO2000026661A1 (en) | 2000-05-11 |
| AU1549000A (en) | 2000-05-22 |
| AU749057B2 (en) | 2002-06-20 |
| JP2003502617A (en) | 2003-01-21 |
| KR20010090813A (en) | 2001-10-19 |
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