DE29805413U1 - Level sensor - Google Patents
Level sensorInfo
- Publication number
- DE29805413U1 DE29805413U1 DE29805413U DE29805413U DE29805413U1 DE 29805413 U1 DE29805413 U1 DE 29805413U1 DE 29805413 U DE29805413 U DE 29805413U DE 29805413 U DE29805413 U DE 29805413U DE 29805413 U1 DE29805413 U1 DE 29805413U1
- Authority
- DE
- Germany
- Prior art keywords
- electrode
- measuring
- level
- reference electrode
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000011156 evaluation Methods 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 10
- 239000003990 capacitor Substances 0.000 claims description 6
- 238000012544 monitoring process Methods 0.000 claims description 3
- 239000011810 insulating material Substances 0.000 claims description 2
- 238000000034 method Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
- G01F23/241—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid for discrete levels
- G01F23/243—Schematic arrangements of probes combined with measuring circuits
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
- G01F23/241—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid for discrete levels
- G01F23/243—Schematic arrangements of probes combined with measuring circuits
- G01F23/244—Schematic arrangements of probes combined with measuring circuits comprising oscillating circuits
Landscapes
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Air Bags (AREA)
- Level Indicators Using A Float (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Description
10 15 20 2510 15 20 25
Äiimelderin:Reporter:
AB Elektronik GmbH Klocknerstraße 58368 WerneAB Elektronik GmbH Klocknerstrasse 58368 Werne
Titel:Title:
FüllstandsgeberLevel sensor
Vertreter:Representative:
Patentanwalt Dr. Helmut Hoffmeister Goldstraße 3 6 48147 MünsterPatent Attorney Dr. Helmut Hoffmeister Goldstraße 3 6 48147 Münster
(A:ABG72_T2.TAT)(A:ABG72_T2.TAT)
1010
FüllstandsgeberLevel sensor
Die Erfindung betrifft eine Vorrichtung zur Füllstandsüberwachung von in Behältnissen befindlichen elektrisch leitfähigen Flüssigkeiten, mit wenigstens einer Elektrode.The invention relates to a device for monitoring the fill level of electrically conductive liquids in containers, with at least one electrode.
20 2520 25
Flüssigkeitsstände leitender Flüssigkeiten werden in bekannter Weise in Behältern mit Niveaugebern auf der Basis von Leitfähigkeitsmessungen überwacht. Hierzu wird der Leitfähigkeitssprung beim Eintauchen zweier Elektroden ausgewertet. Diese Methode wird auch gestaffelt für mehrere diskrete Füllstände durch eine entsprechende Anzahl-von Elektroden realisiert. ■Liquid levels of conductive liquids are monitored in a known manner in containers with level sensors based on conductivity measurements. For this purpose, the jump in conductivity is evaluated when two electrodes are immersed. This method is also implemented in a staggered manner for several discrete fill levels using a corresponding number of electrodes. ■
30 3530 35
Nachteilig ist, daß mit jedem zusätzlich zu messenden Niveau die Anzahl der Elektroden und der Aufwand für eine Auswertung steigt.The disadvantage is that with each additional level to be measured, the number of electrodes and the effort required for evaluation increases.
Es stellt sich daher die Aufgabe, eine Vorrichtung zur Füllständsüberwachung von in Behältnissen befindlichen elektrisch leitenden Flüssigkeiten der eingangs genannten Art so weiter zu entwickeln, daß für die Feststellung einer Vielzahl von Füllständen der meßtechnische Aufwand verringert wird.The task therefore arises of further developing a device for monitoring the fill level of electrically conductive liquids of the type mentioned above in containers in such a way that the measuring effort required to determine a large number of fill levels is reduced.
■■
Diese Aufgabe wird durch die Merkmale des Anspruchs 1 gelöst.This object is solved by the features of claim 1.
Die mit der Erfindung erzielten Vorteile bestehen insbesondere darin, daß für die Auswertung unterschiedlichster Füllstände nur noch drei Elektroden benötigt werden, nämlich die Meßelektrode, die Bezugselektrode und die Referenzelektrode. Möglich wird diese Anordnung durch die eingeführte ReferenzjQ elektrode, die nicht nur die Anzahl der Meßelektroden, sondern auch den Einfluss äußerer Einflußgrößen, wie insbesondere die Leitfähigkeit in der Flüssigkeit beseitigt.The advantages achieved with the invention are in particular that only three electrodes are required for the evaluation of a wide variety of filling levels, namely the measuring electrode, the reference electrode and the reference electrode. This arrangement is made possible by the introduced reference electrode, which not only reduces the number of measuring electrodes, but also eliminates the influence of external influencing factors, such as in particular the conductivity in the liquid.
Durch die in den Unteransprüchen aufgeführten Maßnahmen sind vorteilhafte Weiterbildungen und Verbesserungen an der im Anspruch angegebenen Vorrichtung ermöglicht.The measures listed in the subclaims enable advantageous further developments and improvements to the device specified in the claim.
Ein Ausführungsbeispiel der Erfindung ist in der Zeichnung vereinfacht dargestellt und wird in der nachfolgenden 2Q Beschreibung näher erläutert. Es zeigen Fig. 1 einen Füllstandsgeber in einer schematischAn embodiment of the invention is shown in simplified form in the drawing and is explained in more detail in the following 2Q description. Fig. 1 shows a level sensor in a schematic
dargestellten Schnittdarstellung undshown sectional view and
Fig. 2 einen Füllstandsgeber gemäß Fig. 1 in eingebautem Zustand mit einer Auswerteschaltungs-Fig. 2 a level sensor according to Fig. 1 in installed condition with an evaluation circuit
anordnung.arrangement.
In Fig. 1 ist ein Füllstandsgeber dargestellt, der ausFig. 1 shows a level sensor consisting of
- einer Referenzelektrode 4,
OQ - einer Bezugselektrode 5- a reference electrode 4,
OQ - a reference electrode 5
undand
- einer Meßelektrode 6
besteht.- a measuring electrode 6
consists.
gg Die Referenzelektrode 4 ist von einem Referenzelektrodenisolierelement 2 umgeben, das in ein Elektrodenhalterungselement 1 übergeht, das die Referenzelektrode 4, die Bezugselek-gg The reference electrode 4 is surrounded by a reference electrode insulating element 2, which merges into an electrode holding element 1, which holds the reference electrode 4, the reference electrode
trode 5 und die Meßelektrode 6 hält. Alle drei Elektrode setzen sich außerhalb des Elektrodenhalterungselements 1 in jeweils einen elektrischen Anschluß 3 fort.electrode 5 and the measuring electrode 6. All three electrodes continue outside the electrode holder element 1 into an electrical connection 3.
Die Referenzelektrode 4, die Bezugselektrode 5 und die Meßelektrode 6 erstrecken sich jeweils bis zu einem Nullpegel 7. Das Referenzelektrodenisolierelement 2 hingegen reicht nur bis zu einem Referenzpegel 8, so daß sich für die Meßelektrode 6 ein Meßbereich 9 ergibt, der durch die Länge des Referenzelektrodenisolierelements 2 bestimmt wird.The reference electrode 4, the reference electrode 5 and the measuring electrode 6 each extend to a zero level 7. The reference electrode insulating element 2, on the other hand, only extends to a reference level 8, so that a measuring range 9 results for the measuring electrode 6, which is determined by the length of the reference electrode insulating element 2.
In Fig. 2 ist der in Fig. l beschriebene Füllstandsgeber in ein Behältnis 12 eingebaut. An den elektrischen Anschluß 3 der Bezugselektrode 5 ist ein Multivibrator 11 angeschlossen. ■ ■ ·In Fig. 2, the level sensor described in Fig. 1 is installed in a container 12. A multivibrator 11 is connected to the electrical connection 3 of the reference electrode 5. ■■ ·
An die Elektrode 6 ist eine Meßspannungsauswerteeinrichtung 13, 14, 15, 16 und an die Referenzelektrode 4 eine Referenzspannungsauswerteeinrichtung 17, 18, 19, 20 angeschlossen. Am Ausgang der Meßspannungsauswerteeinrichtung entsteht eine Meßspannung Umess und an der Referenzspannungsauswerteeinrichtung eine Referenzspannung Uref.A measuring voltage evaluation device 13, 14, 15, 16 is connected to the electrode 6 and a reference voltage evaluation device 17, 18, 19, 20 is connected to the reference electrode 4. A measuring voltage Umess is generated at the output of the measuring voltage evaluation device and a reference voltage Uref is generated at the reference voltage evaluation device.
Die Meßspannungsauswerte- und die Referenzspannungsauswerte-2c einrichtung sind gleich aufgebaut.The measuring voltage evaluation device and the reference voltage evaluation device 2c are constructed in the same way.
Zwischen einer an der Elektrode 6, 4 angeschlossenen Leitung und Erde 21 sind parallel zueinander ein Gleichrichterelement 14, 18, ein Kondensatorelement 15, 19 und ein 3q Widerstandselement 16, 20 angeordnet. In der Anschlußleitung liegt zwischen dem Gleichrichterelement 14, 18 und dem Kondensatorelement 15, 19 ein Gleichrichterelement 13, 17.A rectifier element 14, 18, a capacitor element 15, 19 and a 3 q resistance element 16, 20 are arranged parallel to one another between a line connected to the electrode 6, 4 and earth 21. A rectifier element 13, 17 is located in the connecting line between the rectifier element 14, 18 and the capacitor element 15, 19.
Der Multivibrator 11, der ebenfalls an Null 21 liegt, gibt eine Rechteckspannung ab, wodurch die Meßspannung Umess und die Referenzspannung Uref erzeugt werden.The multivibrator 11, which is also connected to zero 21, outputs a square wave voltage, which generates the measuring voltage Umess and the reference voltage Uref.
Prinzipiell nimmt der Stromfluß durch eine leitfähige, das heißt polare Flüssigkeit direkt proportional mit der eingetauchten Elektrodenfläche zu. Damit reichen zur Erfassung des Höchststandes an sich die Bezugselektrode 5 und die Meßelektrode 6 aus. Die Nutzbarkeit des abgegebenen Signals war aber bisher nicht möglich, da die elektrische Leitfähigkeit von Flüssigkeiten in hohem Maße von der Temperatur und der jeweiligen Zusammensetzung der Flüssigkeit abhängen. Hierdurch wird das Signal in hohem Maße beeinflußt und ist damit nicht eindeutig.In principle, the current flow through a conductive, i.e. polar, liquid increases directly proportionally to the immersed electrode area. The reference electrode 5 and the measuring electrode 6 are therefore sufficient to detect the maximum level. However, it has not been possible to use the signal emitted so far, since the electrical conductivity of liquids depends to a large extent on the temperature and the respective composition of the liquid. This has a large influence on the signal and is therefore not clear.
Durch die Einführung der Referenzelektrode 7 werden diese Einflüsse eleminiert. Durch die Ermittlung des Leitfähigkeitsverhältnisses der Grundeinheit "Referenz" zur Meßelek-By introducing the reference electrode 7, these influences are eliminated. By determining the conductivity ratio of the basic unit "reference" to the measuring electrode
, _ trodenanordnung werden die Einflüsse; beseitigt und der Wert lo, _ electrode arrangement, the influences are eliminated and the value lo
des Verhältnisses wird als analoger Füllstand ausgewertet. Die vom Multivibrator 11 abgegebene Wechselspannung in Form einer Rechteckspannung führt in Abhängigkeit vom Flüssigkeitsstand zu einem Aufladen der Kondensatoren 15, 19. Durch eine Verhältnisbildung wird in einfacher Weise ein Spannungsvergleich Umess minus Uref von den über die Meßelektrode 6 bzw. die Referenzelektrode 4 gespeisten Kondensatorenelemente 15, 19 durchgeführt. Als Ausgangssignal des Füllstandes ist jede elektronische Schnittstelle und Schaltfunkton möglich. Die Verhältnisbildung kann sowohl analog, wie im Beispiel, als auch mit digitalen Verfahren durchgeführt werden.The ratio is evaluated as an analog filling level. The alternating voltage emitted by the multivibrator 11 in the form of a square wave voltage leads to a charging of the capacitors 15, 19 depending on the liquid level. By forming a ratio, a voltage comparison Umess minus Uref of the capacitor elements 15, 19 fed via the measuring electrode 6 or the reference electrode 4 is carried out in a simple manner. Any electronic interface and switching function can be used as the output signal of the filling level. The ratio formation can be carried out both analogously, as in the example, and with digital methods.
Die Elektrode 4, 5 und 6 können soweit im Behältnis 12 abgesenkt werden, daß dessen Behältnisboden 22 zugleich das NuIlpotential 7 ausbildet. Das Nullpotential 7 kann aber gegenüber dem Behältnisboden 22 einjustiert werden. Der Referenzpegel 8 wird im wesentlichen durch die Länge des Referenzelektrodenisolierelements 2 bestimmt. Dadurch, daß das Referenzelektrodenisolierelement 2 und das Elektrodenhalterungselement 1 einstückig aus einem Isolierstoff geformt werden, läßt sich der Referenzpegel 8 für sämtliche gefertigte Füllstandsgeber korrekt festlegen.The electrodes 4, 5 and 6 can be lowered into the container 12 so far that the container bottom 22 simultaneously forms the zero potential 7. The zero potential 7 can, however, be adjusted relative to the container bottom 22. The reference level 8 is essentially determined by the length of the reference electrode insulating element 2. Because the reference electrode insulating element 2 and the electrode holder element 1 are formed in one piece from an insulating material, the reference level 8 can be correctly determined for all manufactured level sensors.
Claims (6)
undwhich is substantially parallel to the measuring electrode (6),
and
30connected.
30
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE29805413U DE29805413U1 (en) | 1998-03-25 | 1998-03-25 | Level sensor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE29805413U DE29805413U1 (en) | 1998-03-25 | 1998-03-25 | Level sensor |
Publications (1)
Publication Number | Publication Date |
---|---|
DE29805413U1 true DE29805413U1 (en) | 1998-05-20 |
Family
ID=8054750
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE29805413U Expired - Lifetime DE29805413U1 (en) | 1998-03-25 | 1998-03-25 | Level sensor |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE29805413U1 (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002027280A2 (en) * | 2000-09-26 | 2002-04-04 | Siemens Aktiengesellschaft | Method and device for determining the level of a liquid in a container |
EP1203934A2 (en) * | 2000-10-27 | 2002-05-08 | Siemens Aktiengesellschaft | Level sensor and method to operate a level sensor |
DE202005004920U1 (en) * | 2005-03-23 | 2006-07-27 | BEGO Bremer Goldschlägerei Wilh. Herbst GmbH & Co. KG | Coating device for dental products |
CN100401024C (en) * | 2001-07-13 | 2008-07-09 | 三星电子株式会社 | Water level sensor |
EP2113753A1 (en) * | 2008-04-24 | 2009-11-04 | Continental Automotive GmbH | Device for measuring a probe impedance |
DE102010002739A1 (en) * | 2010-03-10 | 2011-09-15 | Dbk David + Baader Gmbh | Measuring device for detecting the conductivity of a liquid |
CN101694396B (en) * | 2009-01-23 | 2012-04-25 | 南京乐金熊猫电器有限公司 | Water level detecting device and method for dryer |
-
1998
- 1998-03-25 DE DE29805413U patent/DE29805413U1/en not_active Expired - Lifetime
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2002027280A2 (en) * | 2000-09-26 | 2002-04-04 | Siemens Aktiengesellschaft | Method and device for determining the level of a liquid in a container |
WO2002027280A3 (en) * | 2000-09-26 | 2002-06-27 | Siemens Ag | Method and device for determining the level of a liquid in a container |
EP1203934A2 (en) * | 2000-10-27 | 2002-05-08 | Siemens Aktiengesellschaft | Level sensor and method to operate a level sensor |
EP1203934A3 (en) * | 2000-10-27 | 2003-06-04 | Siemens Aktiengesellschaft | Level sensor and method to operate a level sensor |
CN100401024C (en) * | 2001-07-13 | 2008-07-09 | 三星电子株式会社 | Water level sensor |
DE202005004920U1 (en) * | 2005-03-23 | 2006-07-27 | BEGO Bremer Goldschlägerei Wilh. Herbst GmbH & Co. KG | Coating device for dental products |
EP2113753A1 (en) * | 2008-04-24 | 2009-11-04 | Continental Automotive GmbH | Device for measuring a probe impedance |
DE102008020647A1 (en) * | 2008-04-24 | 2009-11-12 | Continental Automotive Gmbh | Device for measuring a probe impedance |
CN101694396B (en) * | 2009-01-23 | 2012-04-25 | 南京乐金熊猫电器有限公司 | Water level detecting device and method for dryer |
DE102010002739A1 (en) * | 2010-03-10 | 2011-09-15 | Dbk David + Baader Gmbh | Measuring device for detecting the conductivity of a liquid |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0338400B1 (en) | Capacitive sensor for determining the liquid level in a container | |
EP3152530B1 (en) | Method and device for monitoring the level of a medium in a container | |
DE19645970C2 (en) | Capacitive level sensor for detecting the level of a fluid located in a container | |
DE3785185T2 (en) | DEVICE AND METHOD FOR MEASURING THE FLOW CHARACTERISTICS OF A PETROLEUM FLOW. | |
DE69001151T2 (en) | Device for level and / or volume measurement of a liquid with a capacitive probe. | |
DE19516809C1 (en) | Capacitive liq. level sensor based on cores of flexible ribbon cable for e.g. milk tank | |
DE2515065C2 (en) | Standing height measuring device for liquid containers | |
DE2740289B2 (en) | Device for monitoring the level of a liquid contained in a container | |
EP1536211B1 (en) | Method for operating a magnetic inductive flowmeter | |
DE19916979A1 (en) | Level measurement method and level sensor | |
EP0261099B1 (en) | Level-measuring instrument for electrically non-conductive liquids | |
DE3524250A1 (en) | ARRANGEMENT FOR CHECKING THE LEVEL OF AN INK TANK | |
EP0740131B1 (en) | Resistive inclination sensor | |
DE29805413U1 (en) | Level sensor | |
DE2819731A1 (en) | Capacitive measurement of highly adhesive media levels in containers - using measurement electrode screening around pole of source connected to transducer | |
DE4312813C2 (en) | Arrangement for capacitive level measurement | |
DE10063557B4 (en) | Method and device for measuring water levels | |
DE2603185C2 (en) | Arrangement for capacitive measurement of the fill level of a container | |
EP1629257B1 (en) | Method and circuit arrangement for detecting the level of a liquid | |
DE2151078C2 (en) | Capacitive level meter | |
DE3522186A1 (en) | MEASURING DEVICE FOR MEASURING THE DEFORMITY OF RED BLOOD BODIES | |
DE3843339A1 (en) | Arrangement for capacitive filling level measurement | |
EP1429124A1 (en) | Method and circuit for capacitive detection and/or determination of the composition of a medium | |
DE4412386C2 (en) | Circuit arrangement for conductive level measurement | |
DE4040332C2 (en) | Multi-electrode stray field method for measuring the electrolytic conductivity of a liquid as well as a multi-electrode stray field sensor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
R207 | Utility model specification |
Effective date: 19980702 |
|
R150 | Utility model maintained after payment of first maintenance fee after three years |
Effective date: 20010622 |
|
R081 | Change of applicant/patentee |
Owner name: AB ELEKTRONIK SACHSEN GMBH, DE Free format text: FORMER OWNER: AB ELEKTRONIK GMBH, 59368 WERNE, DE Effective date: 20020404 |
|
R157 | Lapse of ip right after 6 years |
Effective date: 20041001 |