CN1287129C - Permanent magnetism type excitation method in use for electromagnetic flowmeter - Google Patents
Permanent magnetism type excitation method in use for electromagnetic flowmeter Download PDFInfo
- Publication number
- CN1287129C CN1287129C CN 200410067171 CN200410067171A CN1287129C CN 1287129 C CN1287129 C CN 1287129C CN 200410067171 CN200410067171 CN 200410067171 CN 200410067171 A CN200410067171 A CN 200410067171A CN 1287129 C CN1287129 C CN 1287129C
- Authority
- CN
- China
- Prior art keywords
- switch
- signal
- electrode
- joins
- microprocessor portion
- 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 - Fee Related
Links
- 230000005284 excitation Effects 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims abstract description 19
- 230000005389 magnetism Effects 0.000 title claims description 6
- 239000012530 fluid Substances 0.000 claims abstract description 25
- 230000005684 electric field Effects 0.000 claims abstract description 21
- 238000005070 sampling Methods 0.000 claims abstract description 17
- 238000003780 insertion Methods 0.000 claims description 22
- 230000037431 insertion Effects 0.000 claims description 22
- 239000000523 sample Substances 0.000 claims description 21
- 230000010287 polarization Effects 0.000 abstract description 5
- 230000003321 amplification Effects 0.000 abstract description 2
- 230000003750 conditioning effect Effects 0.000 abstract description 2
- 229910052755 nonmetal Inorganic materials 0.000 abstract description 2
- 238000003199 nucleic acid amplification method Methods 0.000 abstract description 2
- 230000005672 electromagnetic field Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 5
- 238000009413 insulation Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 3
- 230000001360 synchronised effect Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005674 electromagnetic induction Effects 0.000 description 2
- 230000005764 inhibitory process Effects 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 239000004020 conductor Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- 230000000877 morphologic effect Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Images
Landscapes
- Measuring Volume Flow (AREA)
Abstract
The present invention discloses a permanent-magnet excitation method for an electromagnetic flow meter. The method comprises the steps that a permanent magnet generates work magnetic fields which are respectively perpendicular to the flow speed direction and the electrode connecting line direction of an electrically conducting fluid. A flow signal is detected by electrodes and enters a preamplification part which finishes impedance matching and differential amplification; the obtained signal is sent to a signal processing part which finishes signal conditioning. The well-conditioned signal is finally sent to a microprocessor part which finishes flow calculation, and a flow value is sent to a display part to finish flow display. The adoption of an alternating electric field capable of rapid change in a non-sampling time can suppress severe polarization phenomena in measuring a non-metal fluid by traditional DC excitation. Permanent-magnet excitation in a sampling time can avoid the interference of an AC electromagnetic field. The electromagnetic flow meter adopting the method has the advantage of simple structure and can effectively detect the flow signal and can increase the response speed of the electromagnetic flow meter under the condition that an excitation module has zero power consumption.
Description
Technical field
The present invention relates to a kind of exciting method of electromagnetic flowmeter, especially relate to a kind of permanent magnetism type excitation method that is used for electromagnetic flowmeter.
Background technology
Electromagnetic flowmeter is based on Faraday's electromagnetic induction law, during its principle of work motion cutting magnetic line that is conductive fluid in work magnetic field, two ends at fluid produce induced potential e, its direction is determined by the right-hand rule, the magnetic induction density B in its size and magnetic field, fluid in magnetic field length L and the movement velocity u of conductor be directly proportional, if B, L, u three are orthogonal, e=Blu then.
The operate as normal of electromagnetic flowmeter needs the magnetic field of certain intensity.At present, the producing method in magnetic field mainly contains three kinds: DC excitation, power frequency sine wave excitation and square-wave excitation.
DC excitation produces magnetic field or adopts permanent magnet with direct current, and it can produce a constant magnetic field.The great advantage of DC excitation transmitter is to be subjected to the ac magnetic field disturbing effect very little, thereby can ignore the influence of self inductance in the liquid.But, use D.C. magnetic field easily make electrolytic liquid by measuring channel in DC electric field by electrolysis, will cause positive and negative electrode to be surrounded by the ion of opposite polarity respectively like this and polarize, have a strong impact on the operate as normal of instrument.So DC excitation generally only is used to measure nonelectrolyte liquid, as liquid metal etc.
The magnetic field of power frequency sine wave excitation is produced by sinusoidal alternating current, so the magnetic field that produces also is an alternating magnetic field.Adopting the major advantage of the transmitter of power frequency sine wave excitation is the polarization of having eliminated electrode surface, but AC excitation has caused power frequencies such as electromagnetic induction, electrostatic coupling to be disturbed, cause and adopt complicated orthogonal interference to suppress multiple interference protection measures such as circuit, be difficult to eliminate fully the influence of power frequency interference noise, cause electromagnetic flowmeter to be difficult to stablize zero point, measuring accuracy is low, poor reliability.
Square-wave excitation comprises low frequency square wave excitation, three value low frequency square wave excitations and double frequency square wave excitation.
Low frequency square wave excitation technology has changed the morphological feature that power frequency is disturbed, utilize the power frequency synchronous sampling technique, obtain the anti-preferably power frequency interference capability of electromagnetic flowmeter, measuring accuracy and zero stability are higher, but the frequency of low frequency square wave excitation is generally 1/2～1/32 of power frequency, has sacrificed the response speed of electromagnetic flowmeter when obtaining zero stability.
The exciting current signal frequency of three value low frequency square wave excitation technologies is 1/8 of a work frequency, just-zero adopt-negative-zero-positive rule changes, its maximum characteristics are suppressed zeros when the exciting current zero condition, thereby have good zero stability, but the response speed of electromagnetic flowmeter is lower.
In the double frequency square wave excitation technology, exciting current encourages the signal voltage that produces to comprise high and two the low frequency contents of frequency on electrode.Double frequency square wave excitation technology can overcome mud interference and the fluid hydrodynamic noise that fluid media (medium) produces, and the voltage stabilizing at zero point with low frequency Rectangle Wave Excitation Electromagnetic Flow Meter realizes the unification of electromagnetic flowmeter zero stability, antijamming capability and response speed.But the dual-frequency excitation technical sophistication, cost is higher, and only minority producer grasps at present.
Except that the permanent-magnet type DC excitation, other excitation mode all needs electromagnetic flowmeter that the intensity of the electric current of certain intensity with the dependable flow signal is provided, and in general to account for the proportion of whole flowmeter power consumption bigger for the power consumption of excitation module.The demand for development of current techniques realizes Sefe antiexplosion and dry cell power supply, must reduce the power consumption of excitation module effectively.
Summary of the invention
At above situation, the object of the present invention is to provide a kind of permanent magnetism type excitation method that is used for electromagnetic flowmeter, it is simple in structure to adopt the electromagnetic flowmeter of this method to have, and need not exciting current, the characteristics that response speed is fast.
The technical solution adopted for the present invention to solve the technical problems is:
Scheme 1:
1) with two electrodes respectively in opposite directions symmetry be installed on the inner-walls of duct, two permanent magnet symmetries are contained in outside the pipeline, by the work magnetic field that permanent magnet produces, its direction is perpendicular to the flow velocity direction of electrode connecting line and detected fluid; The input control signal S end of switch joins with first output terminal of microprocessor portion, input voltage signal end X1, the Y1 of switch joins with the second and the 3rd output terminal of microprocessor portion respectively, and signal end X, the Y of switch joins with separately electrode respectively; The input signal of prime amplifier part joins with X2, the Y2 of switch respectively, the output terminal of the input end of signal processing and prime amplifier part joins, the output of signal processing and the input end of microprocessor portion join, the 4th output termination display part of microprocessor portion;
2) in the non-sampling time signal end X, the Y of switch respectively with input voltage signal end X1, the Y1 conducting of switch, make two electrodes respectively with the second and the 3rd output terminal conducting of microprocessor portion, on two electrodes, apply alternating electric field;
3) in the sampling time signal end X, the Y of switch respectively with signal end X2, the Y2 conducting of switch, make two electrodes respectively with the first and second input end conductings of preposition amplifier section, thereby cancel the alternating electric field that on electrode, applies, flow signal detects from electrode, behind the flow signal preposition amplifier section of process and signal processing part divisional processing between the electrode, microprocessor portion calculates flow value, and send the display part to show;
4) the applying and cancel by switch and finish of alternating electric field, microprocessor portion produces the intermediate frequency alternating voltage on the second and the 3rd output terminal.
Scheme 2:
1) more than one insertion type probe is perpendicular to the conduit axis direction, insert pipeline along the pipe diameter direction, end one side of electrode close conduit axis in insertion type probe or the outboard shafts of insertion type probe are to symmetric arrangement, permanent magnet is arranged near detected fluid in insertion type probe, the polar orientation of permanent magnet is identical with the insertion type probe axis direction, conductive fluid is flow through by pipe interior, the line direction of electrode is vertical with the flow velocity direction of detected fluid, vertical with the axis direction of insertion type probe, the direction in the work magnetic field that permanent magnet produces is perpendicular to the flow velocity direction of electrode connecting line and detected fluid; The input control signal S end of switch joins with first output terminal of microprocessor portion, input voltage signal end X1, the Y1 of switch joins with the second and the 3rd output terminal of microprocessor portion respectively, and signal end X, the Y of switch joins with separately electrode respectively; The input signal of prime amplifier part joins with X2, the Y2 of switch 4 respectively, the output terminal of the input end of signal processing and prime amplifier part joins, the output of signal processing and the input end of microprocessor portion join, the 4th output termination display part of microprocessor portion;
2), 3), 4) step of method is identical with scheme 1.
The useful effect that the present invention has is: serious polarization phenomena when adopting in the non-sampling time fast-changing alternating electric field can suppress traditional DC excitation to measure nonmetal fluid, the magneto excitation has been avoided the interference of ac magnetic field again in sampling time, adopt the electromagnetic flowmeter of this method simple in structure, flow signal can be under the condition of excitation module zero-power, effectively detected, the response speed of electromagnetic flowmeter can be effectively improved.
Description of drawings
Fig. 1 is the structural representation of the solution of the present invention 1.
Among Fig. 1: 1. permanent magnet, 2. pipeline, 3. electrode, 4. switch, 5. preposition amplifier section, 6. signal processing, 7. microprocessor portion, 8. display part.
Fig. 2 is the voltage signal U of microprocessor portion 7 outputs when applying the one-period alternating electric field in single cycle time T
X1Y1Synoptic diagram;
Fig. 3 is the sequential synoptic diagram that microprocessor portion 7 is controlled sampling and non-sampling when applying the one-period alternating electric field in single cycle time T;
Fig. 4 is the voltage signal U that applies the output of microprocessor portion 7 during alternating electric field of a plurality of cycle in single cycle time T
X1Y1Synoptic diagram;
Fig. 5 applies the control sampling of a plurality of cycle microprocessor portion 7 during alternating electric field and the sequential synoptic diagram of non-sampling in single cycle time T;
Fig. 6 is the structural representation of the solution of the present invention 2.
Among Fig. 6: 1. permanent magnet, 2. pipeline, 3. electrode, 4. switch, 5. preposition amplifier section, 6. signal processing, 7. microprocessor portion, 8. display part, 9. insertion type probe.
Embodiment
The present invention is further described below in conjunction with drawings and Examples.
In the form of implementation of scheme shown in Figure 11, two polarity over against 1, two permanent magnet of permanent magnet that is distributed in pipeline 2 both sides are arranged in the same way.Pipeline 2 inside are provided with insulation course, or the measuring tube that itself is formed by insulating material.Conductive fluid is flow through by measuring tube 2.Perpendicular to the diametric inwall in magnetic field electrode 3 is housed at measuring tube 2, electrode 3 and measuring tube 2 insulation.
The input control signal S end of switch 4 joins with an output terminal of microprocessor portion 7, and input voltage signal end X1, the Y1 of switch 4 and two output terminals of microprocessor portion 7 join, and signal end X, the Y of switch 4 joins with two electrodes 3 respectively.
The input signal of prime amplifier part 5 joins with X2, the Y2 of switch 4 respectively.The output terminal of the input end of signal processing 6 and prime amplifier part 5 joins.An input end of the output of signal processing 6 and microprocessor portion 7 joins.
Permanent magnet 1 produces respectively and conductive fluid flow velocity direction, the vertical work magnetic field of electrode 3 line directions, flow signal is detected by electrode 3, enter preposition amplifier section 5, finish impedance matching and difference amplification by prime amplifier part 5, the signal that obtains is sent into signal processing 6, finishes the conditioning of signal by signal processing 6, and the signal of handling well is finally sent into microprocessor portion 7, finish the calculating of flow by microprocessor portion 7, flow value is sent into the demonstration that flow is finished in display part 8.
Alternating electric field apply and detecting of flow signal controlled switch 4 by microprocessor portion 7 by output control signal S and realized: in the non-sampling time, microprocessor portion 7 output control signal S make and the X1 and X, Y1 and Y formation path of switch apply the polarization of the fast-changing alternating electric field in one or more cycles with effective inhibition electrode 3 by two electrodes 3 on conductive fluid; In the sampling time, microprocessor portion 7 output control signal S make and the X2 and X, Y2 and Y formation path of switch cancel adding alternating electric field to detect flow signal.
Switch 4 can adopt the multichannel analog switch, as CD4052 etc.; Prime amplifier part 5 can adopt the precision operational-amplifier of low drift, high cmrr, high input impedance, as chopper-zero-stabilized type operational amplifier TLC2652 etc.; Signal processing 6, microprocessor portion 7, display part 8 can be with reference to circuit common, and explanation is omitted.
In synoptic diagram shown in Figure 2, microprocessor portion 7 output voltage signal U
X1Y1According to the positive anti-switching of certain frequency, P is a forward voltage, and N is a reverse voltage.In sequential synoptic diagram shown in Figure 3, the work schedule of electromagnetic flowmeter is " P-S-N-S-P " circulation, and P is for applying positive field, and S is for detecting flow signal, and N is for applying reversed electric field.The control signal of switch 4 and forward and reverse voltage provide to keep synchronous by microprocessor portion 7.
In synoptic diagram shown in Figure 4, microprocessor portion 7 output voltage signal U
X1Y1According to the positive anti-switching of certain frequency, P is a forward voltage, and N is a reverse voltage.In sequential synoptic diagram shown in Figure 5, the work schedule of electromagnetic flowmeter carries out a S (detecting flow signal) after being a plurality of " P-N " (or " N-P ") circulation.The control signal of switch 4 and forward and reverse voltage provide to keep synchronous by microprocessor portion 7.Compare with Fig. 3, if the cycle time T of the work schedule of electromagnetic flowmeter is identical, then the frequency of the alternating electric field that Fig. 4 applied is higher, can more effective inhibition polarization of electrode.
In the form of implementation of scheme shown in Figure 62, the insertion type probe 9 of (general 1～8) is perpendicular to pipeline 2 (only expressing the part among Fig. 6) axis direction more than one, insert pipeline 2 along pipeline 2 diametric(al)s, end one side of electrode 3 close pipeline 2 axis in insertion type probe 9 or the outboard shafts of insertion type probe 9 are to symmetric arrangement, permanent magnet 1 is arranged near detected fluid in insertion type probe 9, the polar orientation of permanent magnet 1 is identical with insertion type probe 9 axis directions, conductive fluid is flow through by pipeline 2 inside, the line direction of point electrode 3 is vertical with the flow velocity direction of detected fluid, vertical with the axis direction of insertion type probe 9, the direction in the work magnetic field that permanent magnet 1 produces is perpendicular to the flow velocity direction of electrode 3 lines and detected fluid; The input control signal S of switch 4 end joins with an output terminal of microprocessor portion 7, and input voltage signal end X1, the Y1 of switch 4 and two output terminals of microprocessor portion 7 join, and signal end X, the Y of switch 4 joins with separately electrode 3 respectively; The input signal of prime amplifier part 5 joins with X2, the Y2 of switch 4 respectively, the output terminal of the input end of signal processing 6 and prime amplifier part 5 joins, an input end of the output of signal processing 6 and microprocessor portion 7 joins, another output termination display part 8 of microprocessor portion 7.
The position of insertion type probe 9 installing electrodes 3 is provided with insulation course or itself is formed by insulating material, electrode 3 and insertion type probe 9 insulation.The insertion depth apart from tube wall of electrode 3 is generally 1/2 or 1/8 of measuring tube diameter.
The workflow of scheme 2 is identical with the workflow of scheme 1.
Claims (2)
1. permanent magnetism type excitation method that is used for electromagnetic flowmeter is characterized in that:
1) with two electrodes (3) respectively in opposite directions symmetry be installed on pipeline (2) inwall, two permanent magnets (1) symmetry is contained in outside the pipeline (2), by the work magnetic field that permanent magnet (1) produces, its direction is perpendicular to the flow velocity direction of electrode (3) line and detected fluid; The input control signal S end of switch (4) joins with first output terminal of microprocessor portion (7), input voltage signal end X1, the Y1 of switch (4) joins with the second and the 3rd output terminal of microprocessor portion (7) respectively, and signal end X, the Y of switch (4) joins with separately electrode (3) respectively; The input signal of prime amplifier part (5) joins with signal end X2, the Y2 of switch (4) respectively, the output terminal of the input end of signal processing (6) and prime amplifier part (5) joins, the input end of the output of signal processing (6) and microprocessor portion (7) joins, the 4th output termination display part (8) of microprocessor portion (7);
2) in the non-sampling time signal end X, the Y of switch (4) respectively with input voltage signal end X1, the Y1 conducting of switch (4), make two electrodes (3) respectively with the second and the 3rd output terminal conducting of microprocessor portion (7), on two electrodes, apply alternating electric field;
3) in the sampling time signal end X, the Y of switch (4) respectively with signal end X2, the Y2 conducting of switch (4), make two electrodes (3) respectively with the first and second input end conductings of prime amplifier part (5), thereby cancel the alternating electric field that (3) apply on electrode, flow signal detects from electrode (3), after flow signal process prime amplifier part (5) between the electrode (3) and signal processing (6) are handled, microprocessor portion (7) calculates flow value, and send display part (8) to show;
4) the applying and cancel by switch (4) and finish of alternating electric field, microprocessor portion (7) produces the intermediate frequency alternating voltage on the second and the 3rd output terminal.
2. permanent magnetism type excitation method that is used for electromagnetic flowmeter is characterized in that:
1) more than one insertion type probe (9) is perpendicular to pipeline (2) axis direction, insert pipeline (2) along pipeline (2) diametric(al), end one side of electrode (3) close pipeline (2) axis in insertion type probe (9) or the outboard shafts of insertion type probe (9) are to symmetric arrangement, permanent magnet (1) is arranged near detected fluid in insertion type probe (9), the polar orientation of permanent magnet (1) is identical with insertion type probe (9) axis direction, conductive fluid is flow through by pipeline (2) inside, the line direction of electrode (3) is vertical with the flow velocity direction of detected fluid, vertical with the axis direction of insertion type probe (9), the direction in the work magnetic field that permanent magnet (1) produces is perpendicular to the flow velocity direction of electrode (3) line and detected fluid; The input control signal S end of switch (4) joins with first output terminal of microprocessor portion (7), input voltage signal end X1, the Y1 of switch (4) joins with the second and the 3rd output terminal of microprocessor portion (7) respectively, and signal end X, the Y of switch (4) joins with separately electrode (3) respectively; The input signal of prime amplifier part (5) joins with signal end X2, the Y2 of switch (4) respectively, the output terminal of the input end of signal processing (6) and prime amplifier part (5) joins, the input end of the output of signal processing (6) and microprocessor portion (7) joins, the 4th output termination display part (8) of microprocessor portion (7);
2) in the non-sampling time signal end X, the Y of switch (4) respectively with input voltage signal end X1, the Y1 conducting of switch (4), make two electrodes (3) respectively with the second and the 3rd output terminal conducting of microprocessor portion (7), on two electrodes, apply alternating electric field;
3) in the sampling time signal end X, the Y of switch (4) respectively with signal end X2, the Y2 conducting of switch (4), make two electrodes (3) respectively with the first and second input end conductings of prime amplifier part (5), thereby cancel the alternating electric field that (3) apply on electrode, flow signal detects from electrode (3), after flow signal process prime amplifier part (5) between the electrode (3) and signal processing (6) are handled, microprocessor portion (7) calculates flow value, and send display part (8) to show;
4) the applying and cancel by switch (4) and finish of alternating electric field, microprocessor portion (7) produces the intermediate frequency alternating voltage on the second and the 3rd output terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410067171 CN1287129C (en) | 2004-10-12 | 2004-10-12 | Permanent magnetism type excitation method in use for electromagnetic flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410067171 CN1287129C (en) | 2004-10-12 | 2004-10-12 | Permanent magnetism type excitation method in use for electromagnetic flowmeter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1601236A CN1601236A (en) | 2005-03-30 |
| CN1287129C true CN1287129C (en) | 2006-11-29 |
Family
ID=34666553
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410067171 Expired - Fee Related CN1287129C (en) | 2004-10-12 | 2004-10-12 | Permanent magnetism type excitation method in use for electromagnetic flowmeter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1287129C (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005043718B3 (en) * | 2005-09-13 | 2007-04-19 | Fachhochschule Kiel | Method for measuring the flow rate of a medium |
| CN100434872C (en) * | 2006-05-26 | 2008-11-19 | 李斌 | Signal processing method and system for constant magnetic electromagnetic flowmeter |
| CN103616039B (en) * | 2013-11-27 | 2017-01-04 | 联合汽车电子有限公司 | A kind of characteristic parameter matching method of magneto-electric signal detection system |
| CN103822675A (en) * | 2014-02-26 | 2014-05-28 | 中国科学院合肥物质科学研究院 | Novel electrode liquid metal electromagnetic flowmeter |
| CN104061969B (en) * | 2014-07-08 | 2017-04-05 | 电子科技大学 | A kind of capacitance-type electromagnetic flow signal adapter |
| CN105547384B (en) * | 2015-12-31 | 2019-03-15 | 中国石油天然气股份有限公司 | A kind of constant magnetic electromagnetic flowmeter |
| CN106595782B (en) * | 2016-11-05 | 2019-10-11 | 上海大学 | The electromagnetic flowmeter of ladder multivalue excitation |
| DE102018101568A1 (en) * | 2018-01-24 | 2019-07-25 | Krohne Ag | Magnetic-inductive flowmeter |
| CN111637937A (en) * | 2020-06-01 | 2020-09-08 | 宁波水表(集团)股份有限公司 | Permanent magnet type excitation method for electromagnetic water meter and electromagnetic water meter thereof |
-
2004
- 2004-10-12 CN CN 200410067171 patent/CN1287129C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1601236A (en) | 2005-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1162710C (en) | Non-contact electric current measuring instrument | |
| US7155983B2 (en) | Magnetic flow meter with unibody construction and conductive polymer electrodes | |
| CN1287129C (en) | Permanent magnetism type excitation method in use for electromagnetic flowmeter | |
| CN103323794B (en) | GMR-MEMS integrated weak magnetic sensor adopting plane micro-coil | |
| CN101198840A (en) | Magnetic induced flow measuring device | |
| WO2013168428A1 (en) | Power factor measurement device | |
| JP4404946B2 (en) | Method for measuring the flow rate of a medium | |
| CN105547384A (en) | Constantly magnetic type electromagnetic flowmeter | |
| CN1208617C (en) | Magnetic nondestructive detection method and equipment for oxide inside austenite stainless steel pipe | |
| CN103196503B (en) | Flow meter | |
| CN105182256B (en) | High current, low power magnetic field signal difference acquisition device | |
| CN109459099A (en) | A kind of electrode structure and flowmeter improving electromagnetic flowmeter survey performance | |
| EP3680626A1 (en) | Magnetic flowmeter with media conductivity measurement | |
| CN209927194U (en) | High-precision electromagnetic water meter | |
| RU101817U1 (en) | ELECTROMAGNETIC FLOW METER | |
| RU2343423C1 (en) | Electromagnetic flowmeter | |
| US9459127B2 (en) | Method for operating a magnetic-inductive flow meter with a measuring apparatus for determining measured values which reproduce the field intensity of the electrical field which has been induced by the magnetic field in the flowing medium | |
| CN113093290A (en) | Method for detecting weak secondary field signal under same-frequency strong magnetic interference background | |
| RU2338207C1 (en) | Velocity converter with electric jamming compensation | |
| CN105571662B (en) | A kind of electromagnetic flowmeter signal processing method and processing device | |
| CN111637937A (en) | Permanent magnet type excitation method for electromagnetic water meter and electromagnetic water meter thereof | |
| CN110081940A (en) | A kind of high-precision electromagnetism water meter | |
| US9791305B2 (en) | Apparatus for measuring a liquid flow | |
| CN1140773C (en) | Method for bias placement of excitation part and electromagnetic flow sensor | |
| US6508116B1 (en) | Water bike equipped with speed meter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20061129 Termination date: 20121012 |