WO2005031268A2 - Measuring device for detecting a threshold value - Google Patents

Measuring device for detecting a threshold value Download PDF

Info

Publication number
WO2005031268A2
WO2005031268A2 PCT/EP2004/010405 EP2004010405W WO2005031268A2 WO 2005031268 A2 WO2005031268 A2 WO 2005031268A2 EP 2004010405 W EP2004010405 W EP 2004010405W WO 2005031268 A2 WO2005031268 A2 WO 2005031268A2
Authority
WO
WIPO (PCT)
Prior art keywords
measuring device
threshold value
distance
value
measured value
Prior art date
Application number
PCT/EP2004/010405
Other languages
German (de)
French (fr)
Other versions
WO2005031268A3 (en
Inventor
Hartmut Flämig
Michael Klotzbach
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Publication of WO2005031268A2 publication Critical patent/WO2005031268A2/en
Publication of WO2005031268A3 publication Critical patent/WO2005031268A3/en

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22Indicating 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
    • G01F23/26Indicating 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 capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields
    • G01F23/263Indicating 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 capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields by measuring variations in capacitance of capacitors
    • G01F23/265Indicating 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 capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields by measuring variations in capacitance of capacitors for discrete levels
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F25/00Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
    • G01F25/20Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of apparatus for measuring liquid level

Definitions

  • the invention relates to a measuring device for limit value detection, which monitors an analog measured value for exceeding a threshold value and for falling below the same or a further threshold value and, as a function thereof, generates a logic signal for reporting one of two possible states.
  • Examples of such a measuring device are level switches which report whether a container is full or empty, or light barriers which report whether an object is present in the beam path or not.
  • the measuring device is calibrated to the two possible states, each state being assigned a calibration value. There is a threshold value between the two calibration values and a further threshold value in the event that a switching hysteresis is provided. Depending on whether the current analog measured value exceeds or falls below the threshold value (s), a logic signal reporting the respective status is generated.
  • the measuring device may fail. This problem can be avoided by regular maintenance, but this entails maintenance costs that can be at least partially avoided if the degree of wear could be recognized.
  • the invention is therefore based on the object of specifying a measuring device for limit value detection which itself diagnoses a possible failure due to wear and tear, that is to say wear or contamination, and moreover enables the wear reserve or remaining service life to be specified.
  • the object is achieved in that the measuring device of the type specified at the outset is designed to detect the distance, that is to say the difference, between the analog measured value and the next threshold value in at least one of the two states, and therewith a wear of the Determine measuring device. Due to contamination or wear of the measuring device, the analog measured values in the respective states can move away from the original calibration values. It is critical if the current analog measured value is next to the next
  • Threshold approaches If this is achieved, logical status detection can no longer take place.
  • the measuring device according to the invention evaluates the distance between the analog measured value and the next threshold value and uses this to determine the wear of the measuring device, wear and tear as well as contamination or other disturbances.
  • the analog measured values used to determine the distance are preferably averaged over time, for example by short-term integration.
  • a message is generated when the distance between the analog measured value and the next threshold value falls below a predetermined value.
  • the message can be a maintenance request, a warning, an alarm or the like.
  • the wear or contamination of the measuring device can progress at different speeds, it is not only the current degree of wear that is of interest, but also the temporal development of the wear. Accordingly, the development of the distance between the analog measured value and the next threshold value in the The past is determined by extrapolation, with a message preferably being generated further if the determined remaining service life falls below a predetermined level.
  • FIG. 1 shows an exemplary embodiment of the measuring device according to the invention in the form of a block diagram
  • FIG. 2 shows an example of the generation of the logic signal as a function of the analog measured value
  • Figure 3 shows an example of determining the remaining life of the measuring device.
  • Figure 1 shows a measuring device for limit value detection in the form of a capacitive full level switch.
  • a capacitive probe 2 is attached to a container 1 at a predetermined point, with which it is to be detected whether the filling level of a filling material 3, here a liquid, is above this point (state “1") or below (state “0"). , The probe 2 generates an analog measured value S depending on the respective current fill level.
  • the measuring device is calibrated for both states “1" and "0", whereby in the state “1” the medium 3 just completely covers the probe 2 (fill level H max with the associated analog Kalibrationsmesswert S max) and wherein in the state "0", the filling material 3, the probe 2 just uncovered let (level H m ⁇ n with the associated analog Kalibrationsmesswert S m ⁇ n) • in a threshold value comparison means 4, the respective current analog measured value S to over - or falling below one or two threshold values here Si and S 2 monitors which lie between the two Kalibrationsmesswert S max and S m i n, and which generates a logic signal L in dependency.
  • FIG. 1 the medium 3 just completely covers the probe 2 (fill level H max with the associated analog Kalibrationsmesswert S max) and wherein in the state "0", the filling material 3, the probe 2 just uncovered let (level H m ⁇ n with the associated analog Kalibrationsmesswert S m ⁇ n) • in a threshold value comparison
  • the logic signal L assumes the logical value "1" when the threshold value S x is exceeded and the logic value "0" when the threshold value S 2 is undershot, and thus shows the respective state “1” or “0” on.
  • the two threshold values Si and S 2 are located in predetermined safety distances Ai and A 2 to the Kalibriermess exchange S max and S m i n - due to wear or for example pollution 5 of the probe 2, the measured value S in the state "0", when the probe 2 is barely or no longer covered by the filling material 3, move away from the calibration value S m ⁇ n , as a result of which the distance A 2 to the next threshold value S 2 becomes smaller. If the measured value S thereby reaches the threshold value S 2 , it is no longer possible to change the logic signal L from "1" to "0".
  • the analog measured value S is first time-averaged in a filter 6 each time the state "0" is present.
  • the time-averaged measured value S is then compared in a comparison device 7 with the threshold value S 2 and the distance A 2 between the two is determined.
  • An evaluation device 8 generates a message M when the distance A 2 falls below a predetermined dimension.
  • This predefined dimension can be parameterized and can comprise a plurality of staggered values, so that a maintenance request, a first warning and an alarm can be generated as message M as the distance to A 2 decreases.
  • the message M may, in additional dependence on the temporal development (trend) of the distance A 2 generated in the past by the remaining service life t rest of ER from the past temporal development of the distance A 2 by extrapolation of the measuring device is calculated, i.e. the time until the measured value S in the state
  • the distance can also be changed in a corresponding manner Ai between the measured value S in the "1" state and the threshold value Si are monitored to ensure that the value falls below a predetermined level.
  • the analog measured value S is then averaged over time in a further filter 9 each time the state "1" is present.
  • the time-averaged measured value S is then compared in a further comparison device 10 with the threshold value Si and the distance Ai between the two is determined.
  • the evaluation device 8 generates a message when the distance Ai or the remaining service life of the measuring device determined by extrapolation from the past temporal development of the distance Ai falls below a predetermined value.

Abstract

The invention relates to a measuring device which is used to detect a threshold value and which monitors an analog measuring value to see if it exceeds the threshold value and if it is below the threshold value or another threshold value and which produces, a logical signal in accordance therewith which is used to indicate one of two possible states. The measuring device is configured in such a manner that it can automatically diagnose a possible defect in the measuring device caused by deterioration, i.e. through wear and tear. The measuring device detects the distance between the analog measuring values (S) and the nearest threshold value (S1, S2) in at least one of the two states and determines deterioration and the remainder of the service life of the measuring device.

Description

Beschreibungdescription
Messeinrichtung zur GrenzwerterfassungMeasuring device for limit value acquisition
Die Erfindung betrifft eine Messeinrichtung zur Grenzwerterfassung, die einen analogen Messwert auf Überschreiten eines Schwellenwertes und auf Unterschreiten desselben oder eines weiteren Schwellenwertes überwacht und in Abhängigkeit davon ein logisches Signal zur Meldung eines von zwei mög- liehen Zuständen erzeugt.The invention relates to a measuring device for limit value detection, which monitors an analog measured value for exceeding a threshold value and for falling below the same or a further threshold value and, as a function thereof, generates a logic signal for reporting one of two possible states.
Beispiele für eine solche Messeinrichtung sind Füllstands- schalter, die melden, ob ein Behälter voll oder leer ist, oder Lichtschranken, die melden, ob ein Objekt im Strahlen- gang vorhanden ist oder nicht. Die Messeinrichtung ist dabei auf die zwei möglichen Zustände kalibriert, wobei jedem Zustand jeweils ein Kalibrierwert zugeordnet ist. Zwischen den beiden Kalibrierwerten liegt ein Schwellenwert, und für den Fall, dass eine Schalthysterese vorgesehen ist, ein weiterer Schwellenwert. Je nach dem, ob der aktuelle analoge Messwert den oder die Schwellenwerte über- oder unterschreitet, wird ein den jeweiligen Zustand meldendes logisches Signal erzeugt .Examples of such a measuring device are level switches which report whether a container is full or empty, or light barriers which report whether an object is present in the beam path or not. The measuring device is calibrated to the two possible states, each state being assigned a calibration value. There is a threshold value between the two calibration values and a further threshold value in the event that a switching hysteresis is provided. Depending on whether the current analog measured value exceeds or falls below the threshold value (s), a logic signal reporting the respective status is generated.
Durch Verschmutzung oder. Verschleiß kann es zu einem Ausfall der Messeinrichtung kommen. Dieses Problem kann zwar durch regelmäßige Wartung vermieden werden, jedoch entstehen dabei Instandhaltungskosten, die zumindest teilweise vermieden werden können, wenn der Grad der Abnutzung erkannt werden könnte.Through pollution or. Wear, the measuring device may fail. This problem can be avoided by regular maintenance, but this entails maintenance costs that can be at least partially avoided if the degree of wear could be recognized.
Der Erfindung liegt daher die Aufgabe zugrunde, eine Messeinrichtung zur Grenzwerterfassung anzugeben, die einen möglichen Ausfall durch Abnutzung, also Verschleiß oder Ver- schmutzung, selbst diagnostiziert und darüber hinaus die Angabe der Abnutzungsreserve oder Restlebensdauer ermöglicht. Gemäß der Erfindung wird die Aufgabe dadurch gelöst, dass die Messeinrichtung der eingangs angegebenen Art dazu ausgebildet ist, in mindestens einem der beiden Zustände den Abstand, das heißt die Differenz, zwischen dem analogen Messwert und dem dazu nächsten Schwellenwert zu erfassen und daraus eine Abnutzung der Messeinrichtung zu ermitteln. Durch Verschmutzung oder Verschleiß der Messeinrichtung können sich nämlich die analogen Messwerte in den jeweiligen Zuständen von den ursprünglichen Kalibrierwerten weg bewegen. Dabei ist es kri- tisch, wenn sich der aktuelle analoge Messwert dem nächstenThe invention is therefore based on the object of specifying a measuring device for limit value detection which itself diagnoses a possible failure due to wear and tear, that is to say wear or contamination, and moreover enables the wear reserve or remaining service life to be specified. According to the invention, the object is achieved in that the measuring device of the type specified at the outset is designed to detect the distance, that is to say the difference, between the analog measured value and the next threshold value in at least one of the two states, and therewith a wear of the Determine measuring device. Due to contamination or wear of the measuring device, the analog measured values in the respective states can move away from the original calibration values. It is critical if the current analog measured value is next to the next
Schwellenwert nähert. Wird dieser erreicht, kann nämlich keine logische Zustandserkennung mehr erfolgen. Die erfindungsgemäße Messeinrichtung wertet den Abstand zwischen dem analogen Messwert und dem nächsten Schwellenwert aus und ermittelt daraus die Abnutzung der Messeinrichtung, wobei unter Abnutzung sowohl Verschleiß als auch Verschmutzung oder sonstige Störungen zu verstehen sind.Threshold approaches. If this is achieved, logical status detection can no longer take place. The measuring device according to the invention evaluates the distance between the analog measured value and the next threshold value and uses this to determine the wear of the measuring device, wear and tear as well as contamination or other disturbances.
Um Abnutzungserscheinungen von kurzfristigen aktuellen Stö- rungen unterscheiden zu können, werden die zur Erfassung des Abstandes herangezogenen analogen Messwerte vorzugsweise, beispielsweise durch Kurzzeitintegration, zeitlich gemittelt.In order to be able to distinguish signs of wear from short-term current faults, the analog measured values used to determine the distance are preferably averaged over time, for example by short-term integration.
Entsprechend einer vorteilhaften Weiterbildung der erfin- dungsgemäßen Messeinrichtung wird eine Meldung erzeugt, wenn der Abstand zwischen dem analogen Messwert und dem nächsten Schwellenwert ein vorgegebenes Maß unterschreitet. Je nach Größe dieses vorzugsweise parametrierbaren vorgegebenen Maßes kann es sich bei der Meldung um eine Instandshaltungsanforde- rung, eine Warnung, einen Alarm oder ähnliches handeln.According to an advantageous development of the measuring device according to the invention, a message is generated when the distance between the analog measured value and the next threshold value falls below a predetermined value. Depending on the size of this preferably parameterizable predetermined dimension, the message can be a maintenance request, a warning, an alarm or the like.
Da der Verschleiß oder die Verschmutzung der Messeinrichtung unterschiedlich schnell fortschreiten kann, ist nicht nur der aktuelle Abnutzungsgrad, sondern auch die zeitliche Entwick- lung der Abnutzung von Interesse. Dementsprechend wird in vorteilhafter Weise die Entwicklung des Abstandes zwischen dem analogen Messwert und dem nächsten Schwellenwert in der Vergangenheit durch Extrapolation ermittelt, wobei im Weiteren vorzugsweise eine Meldung erzeugt wird, wenn die ermittelte Restlebensdauer ein vorgegebenes Maß unterschreitet.Since the wear or contamination of the measuring device can progress at different speeds, it is not only the current degree of wear that is of interest, but also the temporal development of the wear. Accordingly, the development of the distance between the analog measured value and the next threshold value in the The past is determined by extrapolation, with a message preferably being generated further if the determined remaining service life falls below a predetermined level.
Zur weiteren Erläuterung der Erfindung wird im Folgenden auf die Figuren der Zeichnung Bezug genommen; im Einzelnen zeigen:To further explain the invention, reference is made below to the figures of the drawing; show in detail:
Figur 1 ein Ausfuhrungsbeispiel der erfmdungsgemaßen Mess- einrichtung in Form eines Blockschaltbildes,FIG. 1 shows an exemplary embodiment of the measuring device according to the invention in the form of a block diagram,
Figur 2 ein Beispiel f r die Erzeugung des logischen Signals in Abhängigkeit von dem erfassten analogen Messwert undFIG. 2 shows an example of the generation of the logic signal as a function of the analog measured value and
Figur 3 ein Beispiel für die Bestimmung der Restlebensdauer der Messeinrichtung.Figure 3 shows an example of determining the remaining life of the measuring device.
Figur 1 zeigt eine Messeinrichtung zur Grenzwerterfassung in Form eines kapazitiven Fullstandsschalters . An einem Behalter 1 ist an einer vorgegebener Stelle eine kapazitive Sonde 2 angebracht, mit der detektiert werden soll, ob der Füllstand eines Füllgutes 3, hier einer Flüssigkeit, über dieser Stelle liegt (Zustand "1") oder darunter (Zustand "0"). Die Sonde 2 erzeugt abhangig von dem jeweils aktuellen Füllstand einen analogen Messwert S. Die Messeinrichtung ist für beide Zustande "1" und "0" kalibriert, wobei im Zustand "1" das Füllgut 3 die Sonde 2 gerade vollständig bedeckt (Füllstand Hmax mit dem zugehörigen analogen Kalibrationsmesswert Smax) und wobei im Zustand "0" das Füllgut 3 die Sonde 2 gerade unbedeckt lasst (Füllstand Hmιn mit dem zugehörigen analogen Kalibrationsmesswert Smιn) • In einer Schwellenwertvergleichseinrichtung 4 wird der jeweils aktuelle analoge Messwert S auf Über- oder Unterschreiten eines oder hier zweier Schwellen- werte Si und S2 überwacht, die zwischen den beiden Kalibrationsmesswert Smax und Smin liegen, und in Abhängigkeit davon ein logisches Signal L erzeugt. Wie Figur 2 zeigt, nimmt das logische Signal L beim Überschreiten des Schwellenwertes Sx den logischen Wert "1" und beim Unterschreiten des Schwellenwerts S2 den logischen Wert "0" an und zeigt so den jeweiligen Zustand "1" bzw. "0" an. Die beiden Schwellenwerte Si und S2 befinden sich in vorgegebenen Sicherheitsabständen Ai bzw. A2 zu den Kalibriermesswerten Smax bzw. Smin- Durch Verschleiß oder beispielsweise Verschmutzung 5 der Sonde 2 kann sich der Messwert S im Zustand "0", wenn die Sonde 2 von dem Füllgut 3 gerade noch nicht oder nicht mehr bedeckt ist, von dem Kalibrierwert Sm±n weg verschieben, wodurch der Abstand A2 zu dem nächsten Schwellenwert S2 geringer wird. Erreicht der Messwert S dabei den Schwellenwert S2, so ist eine Änderung des logischen Signals L von "1" nach "0" nicht mehr möglich.Figure 1 shows a measuring device for limit value detection in the form of a capacitive full level switch. A capacitive probe 2 is attached to a container 1 at a predetermined point, with which it is to be detected whether the filling level of a filling material 3, here a liquid, is above this point (state "1") or below (state "0"). , The probe 2 generates an analog measured value S depending on the respective current fill level. The measuring device is calibrated for both states "1" and "0", whereby in the state "1" the medium 3 just completely covers the probe 2 (fill level H max with the associated analog Kalibrationsmesswert S max) and wherein in the state "0", the filling material 3, the probe 2 just uncovered let (level H mιn with the associated analog Kalibrationsmesswert S m ιn) • in a threshold value comparison means 4, the respective current analog measured value S to over - or falling below one or two threshold values here Si and S 2 monitors which lie between the two Kalibrationsmesswert S max and S m i n, and which generates a logic signal L in dependency. As FIG. 2 shows, the logic signal L assumes the logical value "1" when the threshold value S x is exceeded and the logic value "0" when the threshold value S 2 is undershot, and thus shows the respective state "1" or "0" on. The two threshold values Si and S 2 are located in predetermined safety distances Ai and A 2 to the Kalibriermesswerten S max and S m i n - due to wear or for example pollution 5 of the probe 2, the measured value S in the state "0", when the probe 2 is barely or no longer covered by the filling material 3, move away from the calibration value S m ± n , as a result of which the distance A 2 to the next threshold value S 2 becomes smaller. If the measured value S thereby reaches the threshold value S 2 , it is no longer possible to change the logic signal L from "1" to "0".
Um die Abnutzung, hier die Verschmutzung 5, der Messeinrichtung diagnostizieren zu können, wird der analoge Messwert S zunächst in einem Filter 6 jedes Mal dann zeitlich gemittelt, wenn der Zustand "0" vorliegt. Anschließend wird der zeitlich gemittelte Messwert S in einer Vergleichseinrichtung 7 mit dem Schwellenwert S2 verglichen und der Abstand A2 zwischen beiden ermittelt. Eine Auswerteeinrichtung 8 erzeugt eine Meldung M, wenn der Abstand A2 ein vorgegebenes Maß unterschreitet. Dieses vorgegebene Maß ist parametrierbar und kann mehrere gestaffelte Werte umfassen, so dass mit zunehmend geringer werdendem Abstand zu A2 nacheinander eine Instandhaltungsaufforderung, eine erste Warnung und ein Alarm als Meldung M erzeugt werden können.In order to be able to diagnose the wear, here the contamination 5, of the measuring device, the analog measured value S is first time-averaged in a filter 6 each time the state "0" is present. The time-averaged measured value S is then compared in a comparison device 7 with the threshold value S 2 and the distance A 2 between the two is determined. An evaluation device 8 generates a message M when the distance A 2 falls below a predetermined dimension. This predefined dimension can be parameterized and can comprise a plurality of staggered values, so that a maintenance request, a first warning and an alarm can be generated as message M as the distance to A 2 decreases.
Wie Figur 3 zeigt, kann die Meldung M kann in zusätzlicher Abhängigkeit von der zeitlichen Entwicklung (Trend) des Abstandes A2 in der Vergangenheit erzeugt werden, indem aus der vergangenen zeitlichen Entwicklung des Abstandes A2 durch Extrapolation die Restlebensdauer TRest der Messeinrichtung er- rechnet wird, also die Zeit, bis der Messwert S im ZustandAs Figure 3 shows, the message M may, in additional dependence on the temporal development (trend) of the distance A 2 generated in the past by the remaining service life t rest of ER from the past temporal development of the distance A 2 by extrapolation of the measuring device is calculated, i.e. the time until the measured value S in the state
"0" den Schwellenwert S2 erreicht. Die Meldung M wird dann in Abhängigkeit von der so ermittelten Restlebensdauer TRest erzeugt ."0" reaches the threshold value S 2 . The message M is then in Depending on the thus obtained remaining lifetime T radical generated.
Für den Fall, dass auch im Zustand "1", wenn die Sonde 2 ge- rade von dem Füllgut 3 bedeckt ist, der Messwert S aufgrund von Abnutzung oder sonstigen Erscheinungen von dem Kalibrierwert Smax weg bewegt, kann in entsprechender Weise auch der Abstand Ai zwischen dem Messwert S im Zustand "1" und dem Schwellenwert Si auf Unterschreiten eines vorgegebenen Maßes überwacht werden. Dazu wird dann der analoge Messwert S zunächst in einem weiteren Filter 9 jedes Mal dann, wenn der Zustand "1" vorliegt, zeitlich gemittelt. Anschließend wird der zeitlich gemittelte Messwert S in einer weiteren Vergleichseinrichtung 10 mit dem Schwellenwert Si verglichen und der Abstand Ai zwischen beiden ermittelt. Die Auswerteeinrichtung 8 erzeugt eine Meldung, wenn der Abstand Ai bzw. die durch Extrapolation aus der vergangenen zeitlichen Entwicklung des Abstandes Ai ermittelte Restlebensdauer der Messeinrichtung ein vorgegebenes Maß unterschreiten. In the event that the measurement value S moves away from the calibration value S max due to wear or other phenomena even in the state “1”, when the probe 2 is just covered by the filling material 3, the distance can also be changed in a corresponding manner Ai between the measured value S in the "1" state and the threshold value Si are monitored to ensure that the value falls below a predetermined level. For this purpose, the analog measured value S is then averaged over time in a further filter 9 each time the state "1" is present. The time-averaged measured value S is then compared in a further comparison device 10 with the threshold value Si and the distance Ai between the two is determined. The evaluation device 8 generates a message when the distance Ai or the remaining service life of the measuring device determined by extrapolation from the past temporal development of the distance Ai falls below a predetermined value.

Claims

Patentansprüche claims
1. Messeinrichtung zur Grenzwerterfassung, die einen analogen Messwert (S) auf Überschreiten eines Schwellenwertes (Si) und auf Unterschreiten desselben oder eines weiteren Schwellenwertes (Si, S2) überwacht und in Abhängigkeit davon ein logisches Signal (L) zur Meldung eines von zwei möglichen Zuständen erzeugt, d a d u r c h g e k e n n z e i c h n e t , dass die Messeinrichtung dazu ausgebildet ist, in mindestens einem der beiden Zustände den Abstand (Ai, A2) zwischen dem analogen Messwert (S) und dem dazu nächsten Schwellenwert (Si, S2) zu erfassen und daraus eine Abnutzung der Messeinrichtung zu ermitteln.1.Measuring device for limit value detection, which monitors an analog measured value (S) for exceeding a threshold value (Si) and for falling below the same or a further threshold value (Si, S 2 ) and, depending on this, a logical signal (L) for reporting one of two possible states, characterized in that the measuring device is designed to detect the distance (Ai, A 2 ) between the analog measured value (S) and the next threshold value (Si, S 2 ) in at least one of the two states, and from this one To determine wear of the measuring device.
2. Messeinrichtung nach Anspruch 1, d a d u r c h g e k e n n z e i c h n e t , dass der zur Erfassung des Abstandes (Ai, A2) herangezogene analoge Messwert (S) zeitlich ge- mittelt wird.2. Measuring device according to claim 1, characterized in that the analog measured value (S) used to detect the distance (Ai, A 2 ) is averaged over time.
3. Messeinrichtung nach Anspruch 1 oder 2, d a d u r c h g e k e n n z e i c h n e t , dass eine Meldung (M) erzeugt wird, wenn der Abstand (Ai, A2) ein vorgegebenes Maß unterschreitet .3. Measuring device according to claim 1 or 2, characterized in that a message (M) is generated when the distance (Ai, A 2 ) falls below a predetermined dimension.
4. Messeinrichtung nach einem der vorangehenden Ansprüche, d a d u r c h g e k e n n z e i c h n e t , dass aus der Entwicklung des Abstandes (Ai, A2) in der Vergangenheit durch Extrapolation die Restlebensdauer (TRest) der Messeinrichtung ermittelt wird.4. Measuring device according to one of the preceding claims, characterized in that from the development of the distance (Ai, A 2 ) in the past by extrapolation, the remaining service life (T rest ) of the measuring device is determined.
5. Messeinrichtung nach Anspruch 4, d a d u r c h g e k e n n z e i c h n e t , dass eine Meldung (M) erzeugt wird, wenn die ermittelte Restlebensdauer (TRest) ein vorgegebenes Maß unterschreitet. 5. Measuring device according to claim 4, characterized in that a message (M) is generated when the determined remaining service life (T rest ) falls below a predetermined level.
PCT/EP2004/010405 2003-09-18 2004-09-16 Measuring device for detecting a threshold value WO2005031268A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10343224.8 2003-09-18
DE10343224 2003-09-18

Publications (2)

Publication Number Publication Date
WO2005031268A2 true WO2005031268A2 (en) 2005-04-07
WO2005031268A3 WO2005031268A3 (en) 2005-06-09

Family

ID=34384214

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2004/010405 WO2005031268A2 (en) 2003-09-18 2004-09-16 Measuring device for detecting a threshold value

Country Status (1)

Country Link
WO (1) WO2005031268A2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008035531B4 (en) * 2008-07-29 2012-06-28 Di-Soric Gmbh & Co. Kg Method for determining different operating states of an electronic measuring device
DE202008018263U1 (en) 2008-07-29 2012-07-12 Di-Soric Gmbh & Co. Kg Measuring device with different operating conditions
DE102019200359A1 (en) * 2019-01-14 2020-07-16 Vega Grieshaber Kg METHOD AND DEVICE FOR DETERMINING A THRESHOLD FOR A LIMIT LEVEL SENSOR
DE102021126826A1 (en) 2021-10-15 2023-04-20 Vega Grieshaber Kg Computer-implemented method for classifying a medium, data processing device and measuring device

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4156883A (en) * 1976-06-30 1979-05-29 Erwin Sick Gesellschaft Mit Beschrankter Haftung Optik-Elektronik Light barrier arrangement
EP0501194A1 (en) * 1991-02-26 1992-09-02 Siemens Aktiengesellschaft Method of predetermining the time of maintenance of alarm detectors
US5289011A (en) * 1992-11-30 1994-02-22 Xerox Corporation Sensor control system and method compensating for degradation of the sensor and indicating a necessity of service prior to sensor failure
DE4305195C1 (en) * 1993-02-19 1994-06-30 Schlueter Fotosensorik Gmbh & Light sensor for detecting and counting presence of objects
DE19536026A1 (en) * 1995-09-27 1996-05-23 Siemens Nixdorf Inf Syst Light barrier system with contamination detection
US5539670A (en) * 1986-03-13 1996-07-23 Drexelbrook Controls, Inc. Coating responsive material condition monitoring system
DE19525057C1 (en) * 1995-07-10 1997-02-13 Futronic Gmbh Light barrier device and method for processing a light sensor output signal
US5756876A (en) * 1995-09-28 1998-05-26 Endress + Hauser Gmbh + Co. Method of setting the switching point of a capacitive level limit switch
US6318172B1 (en) * 1997-01-28 2001-11-20 Abb Research Ltd. Capacitive level detector with optimized electrode geometry

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4156883A (en) * 1976-06-30 1979-05-29 Erwin Sick Gesellschaft Mit Beschrankter Haftung Optik-Elektronik Light barrier arrangement
US5539670A (en) * 1986-03-13 1996-07-23 Drexelbrook Controls, Inc. Coating responsive material condition monitoring system
EP0501194A1 (en) * 1991-02-26 1992-09-02 Siemens Aktiengesellschaft Method of predetermining the time of maintenance of alarm detectors
US5289011A (en) * 1992-11-30 1994-02-22 Xerox Corporation Sensor control system and method compensating for degradation of the sensor and indicating a necessity of service prior to sensor failure
DE4305195C1 (en) * 1993-02-19 1994-06-30 Schlueter Fotosensorik Gmbh & Light sensor for detecting and counting presence of objects
DE19525057C1 (en) * 1995-07-10 1997-02-13 Futronic Gmbh Light barrier device and method for processing a light sensor output signal
DE19536026A1 (en) * 1995-09-27 1996-05-23 Siemens Nixdorf Inf Syst Light barrier system with contamination detection
US5756876A (en) * 1995-09-28 1998-05-26 Endress + Hauser Gmbh + Co. Method of setting the switching point of a capacitive level limit switch
US6318172B1 (en) * 1997-01-28 2001-11-20 Abb Research Ltd. Capacitive level detector with optimized electrode geometry

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008035531B4 (en) * 2008-07-29 2012-06-28 Di-Soric Gmbh & Co. Kg Method for determining different operating states of an electronic measuring device
DE202008018263U1 (en) 2008-07-29 2012-07-12 Di-Soric Gmbh & Co. Kg Measuring device with different operating conditions
DE102019200359A1 (en) * 2019-01-14 2020-07-16 Vega Grieshaber Kg METHOD AND DEVICE FOR DETERMINING A THRESHOLD FOR A LIMIT LEVEL SENSOR
DE102019200359B4 (en) * 2019-01-14 2020-11-05 Vega Grieshaber Kg METHOD AND DEVICE FOR DETERMINING A THRESHOLD VALUE FOR A LIMIT LEVEL SENSOR
DE102021126826A1 (en) 2021-10-15 2023-04-20 Vega Grieshaber Kg Computer-implemented method for classifying a medium, data processing device and measuring device

Also Published As

Publication number Publication date
WO2005031268A3 (en) 2005-06-09

Similar Documents

Publication Publication Date Title
EP1155330B1 (en) Method for recognition of signal errors
DE102008043412A1 (en) Device for determining and / or monitoring a process variable of a medium
EP0193732B1 (en) Device for monitoring and controlling switching devices and combinations of switching devices
DE2948776A1 (en) DEVICE FOR DETECTING MAGNETIZABLE, ELECTRICALLY CONDUCTIVE PARTICLES IN AN ELECTRICALLY NON-CONDUCTIVE LIQUID MEDIUM
EP1665483B1 (en) Device for supervising a leakage current of a lighting arrester
EP3381020A1 (en) Method for determining thresholds of a state monitoring unit for a fire detection and/or extinguishing control center, state monitoring unit, and system comprising same
DE102016116426B4 (en) Method for processing a single-edge nibble transmission signal, data receiving device and data transmission device
EP0676055B1 (en) Circuit arrangement for monitoring a plurality of coils
DE102015121576A1 (en) CRYSTAL OSCILLATOR
WO2020207730A1 (en) Locating an earth fault in a dc network
WO2005031268A2 (en) Measuring device for detecting a threshold value
DE19820207A1 (en) Antenna test arrangement for vehicle control system
EP0384209B1 (en) Method for the operation of an ionization smoke detector, and ionization smoke detector
DE2825792C2 (en) Electronic device for checking the function of an electronic yarn clearer
EP1084414A1 (en) Method and device for checking the installation air gap of an active sensor
EP2047447A1 (en) Method and device for the fusion of traffic data when information is incomplete
DE102011075764A1 (en) Evaluation device for analysis of parameters of field device used in industry, has evaluation unit that determines parameters whose values are outside a range of parameter standard, and causes separate output of determined parameters
EP0766088B1 (en) Device for monitoring the rotational speed of a vehicle wheel and at least one other variable of the vehicle
WO2002041974A1 (en) Method for monitoring filtering installations
DE3918925C2 (en)
EP0417392B1 (en) Output circuit for a potentiometer
WO2003040851A2 (en) Arrangement with a peripheral unit connected to a central unit by means of a twin-core line
EP1355740A1 (en) Centrifuge
DE10033687A1 (en) Diagnostic procedure for detecting a faulty contact caused by a fine short-circuit of a lead wire
EP3713030B1 (en) Locating an earth fault in a dc network with multiple load zones

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase