EP1941242A1 - Debitmetre a induction magnetique - Google Patents

Debitmetre a induction magnetique

Info

Publication number
EP1941242A1
EP1941242A1 EP06806799A EP06806799A EP1941242A1 EP 1941242 A1 EP1941242 A1 EP 1941242A1 EP 06806799 A EP06806799 A EP 06806799A EP 06806799 A EP06806799 A EP 06806799A EP 1941242 A1 EP1941242 A1 EP 1941242A1
Authority
EP
European Patent Office
Prior art keywords
control
measuring
evaluation unit
settling time
magnetic field
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.)
Ceased
Application number
EP06806799A
Other languages
German (de)
English (en)
Inventor
Thomas Budmiger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Endress and Hauser Flowtec AG
Original Assignee
Endress and Hauser Flowtec AG
Flowtec AG
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 Endress and Hauser Flowtec AG, Flowtec AG filed Critical Endress and Hauser Flowtec AG
Publication of EP1941242A1 publication Critical patent/EP1941242A1/fr
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/56—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using electric or magnetic effects
    • G01F1/58—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using electric or magnetic effects by electromagnetic flowmeters
    • G01F1/60—Circuits therefor

Definitions

  • the invention relates to a magnetic-inductive flowmeter with a measuring tube, which is traversed by a medium substantially in the direction of the measuring tube axis, with a magnet arrangement which generates a measuring tube penetrating and extending substantially perpendicular to the measuring tube axis, alternating magnetic field with two measuring electrodes arranged essentially on a connecting line, wherein the connecting line is oriented substantially perpendicular to the measuring tube axis and to the magnetic field, and with a control / evaluation unit which determines the volume or mass flow of the medium on the basis of the measuring voltage tapped off at the measuring electrodes determined by the measuring tube.
  • Magnetic-inductive flowmeters exploit the principle of electrodynamic induction for the volumetric flow measurement: vertically to a magnetic field moving charge carriers of the medium induce in equally substantially perpendicular to the flow direction of the medium arranged measuring electrodes a voltage. This measuring voltage induced in the measuring electrodes is proportional to the mean flow velocity of the medium over the cross section of the measuring tube; it is therefore proportional to the volume flow. In the case of a known density of the medium, it is also possible to make a statement about the mass flow of the medium flowing through the measuring tube.
  • the measuring electrodes are usually galvanically or capacitively coupled to the medium.
  • the invention has for its object to improve a magnetic-inductive flowmeter to the effect that it provides information regarding a defect of the meter or individual components of the meter.
  • the object is achieved in that the control / evaluation unit determines the current settling time until a stable measuring state of the measuring device is reached, that the control / evaluation unit reaches the actual settling time with a desired setpoint time for the measuring device until it is reached the stable measurement state compares and that the control / evaluation generates an error message when the actual settling time is greater than the predetermined target settling time.
  • Under settling time is In this case, it is understood that it takes the time it takes for the magnetic-inductive flowmeter to reach a stable operating state after commissioning.
  • the measuring device achieves this stable operating state via an iterative approximation process during which the control variable / control variables for, for example, the optimum sensor-specific switching of the magnetic field are / are determined. Corresponding approximation processes have already become known from the prior art and will be explained in more detail below. If the usual, predetermined settling time of the flowmeter is exceeded at a later time, this is an indication that there is a defect in the flowmeter.
  • control / evaluation unit generates the error message when the deviation between the current actual settling time and the setpoint settling time until reaching a stable measuring state of the measuring device is outside a predetermined tolerance value.
  • the control / evaluation unit generates the error message that the mechanical stability of the magnet arrangement is disturbed due to an actual settling time exceeding the predetermined target settling time until a stable measuring state of the measuring device is reached .
  • an extended settling time is an indication that e.g. the attachment of the pole pieces of Magnetanordung is no longer given.
  • the vibrations caused by the mechanical instability when switching the magnetic field substantially lengthen the settling time of the coil current. According to the invention, therefore, a mechanically unstable magnet system is reliably detected by monitoring the settling time.
  • the target settling time is the time it takes for the measuring device to have determined an optimum value for at least one control variable.
  • the control variable is a sensor-specific variable, in particular the magnetic field strength or the coil current flowing through a coil arrangement of the magnet arrangement after switching the magnetic field.
  • the sensor-specific variable or the control variable preferably via an iterative approximation process, wherein the approximation process starts with a predetermined starting value of the sensor-specific variable or the control variable.
  • the sensor-specific variable or the control variable, which the control / evaluation unit determines iteratively is the minimum period of time it takes to reach that through the coil arrangement flowing current has a substantially constant current end value has reached.
  • the switching of the magnetic field is controlled by the current flowing through the coils of the magnet assembly coil current.
  • the current profile in the coil arrangement corresponds to the course of the magnetic field. Due to eddy currents, which occur during the switching of the magnetic field in the pole shoes and cores of the coil assembly, deviations from the ideal case occur in reality.
  • the coil current measured outside the coil arrangement therefore corresponds to the sum of the current flowing in the coil and the current generated by the eddy currents. If the current measured outside the coil arrangement is used as the controlled variable, then the current is not constant but the magnetic field is constant. This applies as long as the eddy currents have not decayed.
  • EP 0 969 268 A1 proposes not to use the current directly for tracking the voltage across the coil arrangement.
  • an overvoltage is applied to the coil assembly upon switching the magnetic field for a rise time.
  • the duration of the over-voltage is successively adjusted so that the current maximum is reached with the end of the rise time, so that no further increase of the coil current occurs.
  • the coil current asymptotically approaches the final current value.
  • the magnetic field has a constant maximum magnetic field value corresponding to the constant current end value when the current maximum is reached.
  • the duration of the switching phase is given by the characteristic of the coil current. Since the stability of the measuring signal u.a.
  • the measured values determined during a switching phase are used to optimize the period of time sh ⁇ il for the subsequent switching phase.
  • the procedure is as follows:
  • the control / evaluation unit sets during a first switching operation for a predetermined period of time
  • control / evaluation unit detects a plurality of current measured values within the predetermined period of time
  • control / evaluation unit checks the actual settling time in predetermined periodic or aperiodic intervals.
  • control / evaluation unit triggers the determination or the verification of the actual settling time by means of a command.
  • FIG. 1 a schematic representation of the flowmeter according to the invention
  • FIG. 2 shows a flow chart for controlling the control / evaluation unit.
  • Fig. 1 shows a schematic representation of an embodiment of the flowmeter according to the invention 1.
  • the measuring tube 2 is flowed through by the medium 11 in the direction of the measuring tube axis 3.
  • the medium 11 is at least to a small extent electrically conductive.
  • the measuring tube 2 itself is made of a non-conductive material, or it is lined at least on its inner surface with a non-conductive material.
  • the magnetic field B oriented substantially perpendicular to the flow direction of the medium 11 is generated via the diametrically arranged coil arrangement 6, 7 or via two electromagnets. Under the influence of the magnetic field B, charge carriers located in the medium 11 migrate, depending on the polarity, to one of the two oppositely poled measuring electrodes 4, 5.
  • the voltage which builds up on the measuring electrodes 4, 5 is proportional to the flow velocity of the medium 11, averaged over the cross section of the measuring tube 2. H. it is a measure of the volume flow of the medium 11 in the measuring tube 2.
  • the measuring tube 2 is incidentally via connecting elements, for. As flanges, which are not shown separately in the drawing, connected to a pipe system through which the measuring medium 11 flows.
  • the measuring electrodes 4, 5 are in direct contact with the measuring medium 11;
  • the coupling can also be capacitive, as already mentioned above.
  • the connection between the coil arrangements 6, 7 and the control / evaluation unit 8 takes place via the connection lines 14, 15.
  • the control / evaluation unit 8 is connected via the connection line 16 to an input / output unit 9.
  • the evaluation / control unit is assigned to the memory unit 10.
  • a flowchart for controlling the control / evaluation unit 8 is shown.
  • the starting values for the individual control variables are each provided as a function of the iterative approximation process used. If, for example, the iterative approximation process proposed in EP 0 969 268 A1 is used, start values for the rise time during which an overvoltage is applied to the coil arrangement and the overvoltage itself must be specified.
  • the desired settling time is determined via the selected iterative approximation process; under program item 21, the determined target settling time is stored.
  • the measuring device 1 is determined at a later time - for example, after a re-commissioning of the flowmeter 1 - the actual control time until reaching a stable operating state and compared with the stored target delay time. If the actual control time exceeds the predetermined setpoint control time by a period ⁇ , this check is made under program point 23, this is an indication of a mechanical defect on the measuring device which has effects on the correct switching of the magnetic field , In this case, an error message is output at program point 24.
  • the defect is, for example, a loosening of the magnet assembly due to a loose attachment. Due to the mechanical instability of the magnet arrangement and the vibrations excited subsequently when the magnetic field is switched on, the regulation of the coil current and consequently the desired settling time are prolonged.
  • the actual settling time is again determined at a suitable later point in time and compared with the predetermined target settling time.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Volume Flow (AREA)

Abstract

L'invention concerne un débitmètre (1) de l'écoulement de l'eau à induction magnétique, comprenant un tuyau de mesure (2), à travers lequel s'écoule un fluide (11) sensiblement dans le sens de l'axe (3) du tuyau, comprenant un dispositif magnétique (6, 7) qui produit un champ magnétique alternatif, introduit dans le tuyau de mesure (2) et passant de manière sensiblement verticale par rapport à l'axe (3) du tuyau, lequel comprend deux électrodes (4, 5) de mesure disposées dans une ligne de jonction, cette dernière étant sensiblement verticale par rapport à l'axe (3) du tuyau de mesure et au champ magnétique. Ledit appareil comprend une unité de réglage- d'évaluation (8), qui détermine, en fonction de la tension de mesure prélevée sur les électrodes (4, 5) de mesure, le volume ou le débit de la masse du fluide (11) à travers le tuyau (2) de mesure. L'objectif de l'invention est de détecter rapidement une défaillance du débitmètre (1). A cet effet, l'unité de réglage et d'évaluation (8) détermine la durée de réglage réelle, nécessaire pour obtenir un mode de mesure stable du débitmètre (1). Puis, l'unité (8) compare la durée de réglage réelle et une durée de réglage théorique prédéterminée pour le débitmètre (1), jusqu'à l'obtention d'un mode de mesure stable, enfin elle produit un message d'erreur, lorsque la durée de réglage réelle est supérieure à la durée de réglage théorique prédéterminée.
EP06806799A 2005-10-20 2006-09-22 Debitmetre a induction magnetique Ceased EP1941242A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102005050655A DE102005050655A1 (de) 2005-10-20 2005-10-20 Magnetisch-induktives Durchflussmessgerät
PCT/EP2006/066638 WO2007045540A1 (fr) 2005-10-20 2006-09-22 Debitmetre a induction magnetique

Publications (1)

Publication Number Publication Date
EP1941242A1 true EP1941242A1 (fr) 2008-07-09

Family

ID=37467457

Family Applications (1)

Application Number Title Priority Date Filing Date
EP06806799A Ceased EP1941242A1 (fr) 2005-10-20 2006-09-22 Debitmetre a induction magnetique

Country Status (6)

Country Link
US (1) US8220342B2 (fr)
EP (1) EP1941242A1 (fr)
CN (1) CN101310166B (fr)
DE (1) DE102005050655A1 (fr)
RU (1) RU2396522C2 (fr)
WO (1) WO2007045540A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102116647B (zh) * 2009-12-31 2013-08-14 意法半导体研发(深圳)有限公司 流量计
DE102014107200A1 (de) * 2014-05-22 2015-11-26 Endress + Hauser Flowtec Ag Vorrichtung zum Messen des Volumenstroms eines Fluids
CN113029542A (zh) * 2021-03-17 2021-06-25 中国航发动力股份有限公司 一种喷嘴流量测定方法

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2030713C1 (ru) 1992-01-23 1995-03-10 Владимир Борисович Большаков Электромагнитный расходомер
EP0969268A1 (fr) * 1998-07-03 2000-01-05 Endress + Hauser Flowtec AG Méthode de régulation de courant de bobine d'un capteur de débit électromagnétique
DE19917268B4 (de) * 1999-04-16 2005-07-14 Siemens Flow Instruments A/S Verfahren zum Überprüfen eines elektromagnetischen Durchflußmessers und elektromagnetische Durchflußmesseranordnung
DE10312058A1 (de) * 2003-03-18 2004-09-30 Endress + Hauser Flowtec Ag, Reinach Vorrichtung zum Messen des Volumenstroms eines Messmediums in einem Messrohr
DE102005028723A1 (de) * 2005-06-20 2006-12-28 Endress + Hauser Flowtec Ag Magnetisch-induktives Durchflussmessgerät
DE102006054635A1 (de) * 2006-11-17 2008-05-21 Endress + Hauser Flowtec Ag Vorrichtung zum Messen des Volumen- oder Massestroms eines Mediums in einer Rohrleitung

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2007045540A1 *

Also Published As

Publication number Publication date
DE102005050655A1 (de) 2007-04-26
CN101310166B (zh) 2011-12-14
RU2396522C2 (ru) 2010-08-10
US20100281996A1 (en) 2010-11-11
US8220342B2 (en) 2012-07-17
WO2007045540A1 (fr) 2007-04-26
CN101310166A (zh) 2008-11-19
RU2008119820A (ru) 2009-11-27

Similar Documents

Publication Publication Date Title
EP3150974B1 (fr) Procede de reglage de l'intensite constante d'un champ magnetique sur un debitmetre inductif magnetique et debitmetre inductif magnetique correspondant
EP1792144B1 (fr) Procede de controle d'un debitmetre magneto-inductif
WO2007020111A1 (fr) Debitmetre a induction magnetique
WO2007033697A1 (fr) Procede pour faire fonctionner un dispositif electromagnetique de mesure de debit, et dispositif electromagnetique de mesure de debit correspondant
EP3171139B1 (fr) Procede de mesure de debit a l'aide d'un debitmetre magneto-inductif
EP1460394B1 (fr) Verfahren zum Regeln des Spulenstroms von magnetisch-induktiven Durchflussaufnehmern
WO2015176891A1 (fr) Dispositif de mesure du débit volumétrique d'un fluide
EP2024715B1 (fr) Procédé et dispositif pour déterminer le débit volumique ou massique
WO2019192799A1 (fr) Débitmètre à induction magnétique et point de mesure comprenant ce type de débitmètre à induction magnétique
DE102012105716A1 (de) Verfahren zur Steuerung eines Spulenstroms eines magnetisch- induktiven Durchflussmessgerätes
WO2007003461A1 (fr) Procede pour determiner le point de fonctionnement d'un debitmetre magnetique inductif
DE102005028723A1 (de) Magnetisch-induktives Durchflussmessgerät
WO1998045670A1 (fr) Appareil magneto-inductif de mesure du debit de milieux en ecoulement
EP1941242A1 (fr) Debitmetre a induction magnetique
WO2014026841A1 (fr) Débitmètre électromagnétique
EP1275940B1 (fr) Méthode pour commander un débitmètre magnéto-inductif
EP1108988A1 (fr) Procédé et dispositif pour la détermination d'un débit d'un fluide dans un conduit de mesure
DE102006016564A1 (de) Vorrichtung zum Bestimmen des Volumen- oder Massestroms eines Mediums
WO2005012842A1 (fr) Procede de determination magneto-inductive du debit d'un agent
DE102008034566A1 (de) Elektromagnetischer Durchflussmesser sowie Verfahren zum Betrieb eines elektromagnetischen Durchflussmessers
EP4441470A1 (fr) Débitmètre à induction magnétique
EP4441471A1 (fr) Dispositif de mesure de débit magnéto-inductif
DE102021131696A1 (de) Verfahren zum Betreiben einer magnetisch-induktiven Durchflussmessvorrichtung
DE102008034565A1 (de) Elektromagnetischer Durchflussmesser sowie Verfahren zum Betrieb eines elektromagnetischen Durchflussmessers

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20080407

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20150518

REG Reference to a national code

Ref country code: DE

Ref legal event code: R003

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 20151029