FMG-J Insertion Electromagnetic Flowmeter|Electromagnetic Flowmeter Flow Knowledge

FMG-J Insertion Electromagnetic Flowmeter|Electromagnetic Flowmeter Flow Knowledge

Applicable to large pipe diameters above DN100 (DN100~DN3000) | Installation method (Tee joint/flange connection) | Various output methods (4~20mA+Rs485+Pulse) | Liquid flow meter didyouknow translat

Electromagnetic flowmeters use Faraday's law of induction to detect flow. FGT's main business is the production of industrial flowmeters.


FMG-J Insertion Electromagnetic Flowmeter

  • LCD display function
  • Display interface: English or Chinese
  • Easy to set up and install/various size range.
  • High accuracy: ±1.5% of reading (RD)
  • Flow direction function: forward or reverse
  • Alarm function: excitation, no liquid pipe alarm.
  • Installation method: adjustable fixed type

/The principle of plug-in electromagnetic flowmeter/Flowmeter function

Principle Electromagnetic flowmeter characteristics Why water can conduct electricity

Insertion Electromagnetic FlowmeterThe working principle is based on Faraday's law of electromagnetic induction, which can provide bidirectional high-precision measurement. It is an ideal flowmeter for leak detection and is widely used in many fields. Today, I will mainly introduce the measurement objects and characteristics of the plug-in electromagnetic flowmeter, hoping to help everyone.

Insertion Electromagnetic FlowmeterMeasurement object

Measuring tube, electrodes, excitation coil, iron core and yoke housing. It is used to measure the flow of conductive fluids in tap water, steel, petroleum, chemical industry, electric power, industry, water conservancy and other departments, as well as corrosive conductive liquids such as acid, alkali and salt.

Plug-in electromagnetic flowmeter entity diagram
Tee joint type | Flange joint type

Insertion Electromagnetic FlowmeterFeatures

1. The measurement is not affected by changes in fluid density, viscosity, temperature, pressure and conductivity;

2. There are no obstructing flow parts in the measuring tube, no pressure loss, and the requirements for straight pipe sections are low;

3. The nominal diameter of the series is DN15~DN3000. There are various options for sensor lining and electrode materials;

4. The converter adopts a novel excitation method, with low power consumption, stable zero point and high accuracy. The flow range can reach 1500:1;

5. The converter can be combined with the sensor to form an integral type or a separate type;

6. The converter adopts 16-bit high-performance microprocessor, 2x16LCD display, convenient parameter setting and reliable programming;

7. The flowmeter is a two-way measurement system, with three built-in totalizers: forward total, reverse total and difference total; it can display. Zhuang, reverse flow, and has a variety of outputs: current, pulse, digital communication , HART;

8. The converter adopts surface mount technology (SMT), with self-test and self-diagnosis functions

/Flowmeter Principle Introduction/Electromagnetic Flowmeter Installation/Tap Water Flowmeter

Minutes to immediately understand various flowmeter principles Liquid flowmeters

Electromagnetic Flowmeter(Electromagnetic Flowmeters, EMF for short) is a new type of flow measuring instrument developed rapidly with the development of electronic technology in the 1950s and 1960s. Electromagnetic flowmeter is an instrument that uses the principle of electromagnetic induction to measure the flow of conductive fluid according to the electromotive force induced by the conductive fluid passing through an external magnetic field.

Electromagnetic FlowmeterThe principle is based on Faraday's law of electromagnetic induction. When the conductor moves in the magnetic field to cut the magnetic field lines, an induced potential will be generated in the conductor, and the magnitude of the induced potential is proportional to the effective length of the conductor in the magnetic field and the speed of the conductor in the magnetic field perpendicular to the direction of the magnetic field. In the same way, when the conductive fluid flows in the vertical direction in the magnetic field and cuts the magnetic induction line, an induced potential will also be generated on the electrodes on both sides of the pipe.

The volume flow rate is equal to the product of the fluid velocity v and the pipe cross-sectional area (πD²)/4. When the pipe diameter D is fixed and the magnetic induction intensity B is kept constant, the measured volume flow rate has a linear relationship with the induced potential. If an electrode is inserted on both sides of the pipe, an induced potential can be introduced, and the volume flow can be obtained by measuring the magnitude of this potential.

one,Electromagnetic Flowmeterstructure

Electromagnetic FlowmeterThe structure is mainly composed of magnetic circuit system, measuring catheter, electrode, shell, lining and converter.

1. Electromagnetic electrode system: its function is to generate a uniform DC or AC magnetic field. The DC magnetic circuit is realized by a permanent magnet, which has the advantages of simple structure and less interference by the AC magnetic field, but it is easy to polarize the electrolyte liquid in the measuring catheter, so that the positive electrode is surrounded by negative ions, and the negative electrode is surrounded by positive ions. Surrounding, that is, the polarization phenomenon of the electrodes, and leads to an increase in the internal resistance between the two electrodes, thus seriously affecting the normal operation of the instrument. When the diameter of the pipeline is large, the permanent magnet is correspondingly large, cumbersome and uneconomical, so the electromagnetic flowmeter generally adopts an alternating magnetic field, and is generated by the excitation of a 50HZ power frequency power supply.

2. Lining: There is a complete electrical insulating lining on the inner side of the measuring conduit and the sealing surface of the flange. It directly contacts the liquid to be measured, and its function is to increase the corrosion resistance of the measuring conduit and prevent the induced potential from being short-circuited by the wall of the metal measuring conduit. Lining materials are mostly corrosion-resistant, high-temperature-resistant, wear-resistant PTFE plastics, ceramics, etc.

3. Converter: The induced potential signal generated by the liquid flow is very weak and is greatly affected by various interference factors. The function of the converter is to amplify and convert the induced potential signal into a unified standard signal and suppress the main interference signal. Its task is to amplify and convert the induced potential signal Ex detected by the electrode into a unified standard DC signal.

4. Measuring catheter: its function is to let the measured conductive liquid pass through. In order to make the magnetic flux be shunted or short-circuited when the magnetic field line passes through the measuring conduit, the measuring conduit must be made of materials with non-magnetic conductivity, low electrical conductivity, low thermal conductivity and certain mechanical strength. Plastic, aluminum, etc.

5. Electrode: Its function is to draw out the induced potential signal proportional to the measured value. The electrodes are generally made of non-magnetic stainless steel and are required to be flush with the lining so that the fluid can pass unobstructed. Its installation position should be in the vertical direction of the pipeline to prevent sediment from accumulating on it and affecting the measurement accuracy.

6. Shell: Made of ferromagnetic material, it is the outer cover of the excitation coil of the distribution system, and isolates the interference of external magnetic fields.

2. Principle

1. Basic principles

Electromagnetic FlowmeterThe basic principle is based on Faraday's law of electromagnetic induction

Electromagnetic Flowmeterworking principle:Electromagnetic FlowmeterAccording to the principle of electromagnetic induction of the flange, a pair of detection electrodes are installed on the pipe wall which is perpendicular to the axis of the measuring tube and the line of magnetic force. When the conductive liquid moves along the axis of the measuring tube, the conductive liquid cuts the magnetic line of force to generate an induced potential, which is determined by Two detection electrodes are detected, the value is proportional to the flow rate, and its value is: E=B*V*D*K

The sensor transmits the induced electromotive force as a flow signal to the converter. After signal processing such as amplification, conversion filtering, etc., the instantaneous flow and cumulative flow are displayed by a dot-matrix liquid crystal with backlight.

E : Induced electromotive force

K : meter constant

B : Magnetic induction intensity

D : Measuring tube diameter

V : average flow velocity


2. Three important concepts

(1) Only conductive medium can be measured

Conductivity limitation б≥ 1-5us/cm (water>20us/cm)

(Use special meter for low conductivity)

Cannot measure non-conductive medium, such as gas, oil, such as medium containing a large amount of

gas, producing severe fluctuations in measurement

(2) There must be a magnetic field

The excitation current flows through the upper and lower excitation coils of the measuring tube to generate a magnetic field. Excitation coil open circuit,

The flowmeter does not work, and the stability of the excitation current directly affects the measurement of the instrument

The measuring tube must be a non-magnetic material to ensure that the magnetic field passes through the tube

(Measuring tube should be made of stainless steel)

(3) The actual measured value is the fluid flow rate

The electromagnetic flowmeter actually measures the flow rate of the medium (it is the velocity is the flowmeter)

Measuring the volume flow of a medium

Proficient in flow rate conversion

3. Two important parts

Sensors and secondary instruments are two essential components of electromagnetic flowmeters.

Flowmeter Price / Flowmeter Type / Gas Flowmeter

Biogas Flow Meter / Tap Water Flow Meter

What is the use of electromagnetic flowmeter? | Our performance



Additional information

Types of


Installation method


Output method

digital, analog


Flow Meter

Technical Specifications

Model FMG-J FMG-I model FMG-J FMG-I
Adjustable Type Fixed Type Telescopic Fixed
Size(mm) 100~3000 size(mm) 100~3000
Application Raw Water,Pure Water,Waste Water,Liquid of Conductivity >50μS/cm App types Raw water, purified water, waste water, conductivity>50μs/cmthe liquid
Peak flow rate 0.1~10.0 m/s flow rate 0.1~10.0 m/s
Conductivity to be more than 50μS/cm Conductivity more than the 50μS/cm
Accuracy ± 1.5% of  reading precision ± 1.5% of  reading
Repeatability ± 0.25% of reading Repeatability ± 0.25% of reading
Insertion tube size(mm) ø32mm or ø50mm Insertion tube diameter(mm) ø32mmorø50mm
Material of signal electrode and grounding electrode Mo-containing stainless steel,Hastelloy B,Hastelloy C,Titanium alloy,Tantalum alloy,Platinum-iridium alloy,Stainles-steel-coated wolfram Material of electrode and ground electrode Molybdenum-containing stainless steel, HastelloyB, HastelloyC, titanium, tantalum, platinum-iridium alloy
Material of Piping Carbon Steel,Stainless steel 304,No piping Measuring tube material Carbon steel, stainless steel304, without measuring tube
Material of sensor Stainless steel 1Cr18Ni9Ti Sensor material stainless steel 1Cr18Ni9Ti
Max.Temperature with Lining material Polytetrafluoroethylene <70℃ With protective lining material     Maximum temperature resistance Teflon <70℃
Polyvinyl fluoride <70℃ polyvinyl fluoride <70℃
Fluorinated ethylene-propylene <70℃ Fluorinated vinyl – acrylic <70℃
Polychloroprene rubber <70℃ Neoprene <70℃
Polyurethane <70℃ Polyurethane <70℃
Max.Pressure DN100~DN3000 1.6Mpa Maximum withstand voltage DN100~DN3000 1.6Mpa
Display Line 2 Line with LCD display panel Column backlightLCDshow
Protection IP68 for Body and IP65 for Display Protection level IP68 Measuring tube material and IP65 display panel
Output 4~20mA or 0~10mA or pulse output signal 4~20mA or 0~10mA or Pulse output
Communication RS485(Option),RS232(Option),Hart(Option) with lightning protection communication signal RS485(Shop),RS232(Shop),Hart(Shop)
Parts Vavle With Without Accessories Ball valve have without
Power supply AC 85~265V 45~63Hz or DC 11~40V power supply comminicate 85~265V 45~63Hz or DC 11~40V

Flow range

DN Flow Range(m3/h)
(mm) Qmin(0.5m/s) Q(1.0m/s) Q(2.0m/s) Q(3.0m/s) Q(4.0m/s) Q(5.0m/s) Q(6.0m/s) Q(7.0m/s) Q(8.0m/s) Q(9.0m/s) Qmax(10 m/s)
100 20 39 79 117 157 196 235 275 314 353 393
125 29 57 115 171 229 286 343 401 458 515 573
150 40 80 161 240 320 400 480 561 641 721 802
200 62 124 250 374 498 623 747 872 997 1121 1247
250 91 181 364 545 726 909 1090 1271 1454 1635 1818
300 127 254 509 763 1017 1272 1526 1780 2035 2289 2545
350 173 346 692 1039 1385 1731 2077 2423 2769 3116 3464
400 226 452 904 1356 1809 2261 2713 3165 3617 4069 4523
450 286 572 1145 1717 2289 2861 34347 4006 4578 5150 5725
500 353 707 1413 2120 2826 3533 4239 4946 5652 63559 7069
600 509 1017 2035 3052 4069 5087 6104 7122 8139 9156 10180
700 692 1385 2769 4154 5539 6924 8308 9693 11078 12463 13847
800 904 1809 3617 5426 7265 9043 10852 12660 14469 16278 18086
900 1145 2289 4578 6867 9156 11445 13734 16023 18312 20602 22891
1000 1413 2826 5652 8478 11304 14130 16956 19782 22608 25434 28260
1200 2035 4069 8139 12208 16278 20347 24417 28486 32556 36625 40694
1400 2769 5539 11078 16617 22156 27695 33234 38773 44312 49851 55390
1600 3617 7235 14469 22156 28938 36173 43407 50642 57876 65111 72346
1800 4578 9156 18312 28938 36625 45781 54937 64094 73250 82406 91562
2000 5652 11304 22608 33912 45216 56520 67824 79128 90432 101736 113040
2200 6839 13678 27356 41034 54711 68389 82067 95745 109423 123101 136778
2400 8139 16278 32556 48833 65111 81389 97667 113944 130222 146500 162778
2600 9552 19104 38208 57311 76415 955519 114623 133726 152830 171934 191038
2800 11078 22156 44312 66468 88623 110779 132935 155091 177247 199403 221558
3000 12717 25434 50868 76302 101736 127170 152604 178038 203472 228906 254340

Order model

Order Information
FMG Code Model Type
J Adjustable Type(Standard type)
I Fixed Type
Code Electrode Type
N Standard type
Code Piping Type
XXXX 100~3000mm
Code Electrode material
0 Mo-containing stainless steel(Standard Type)
1 Hastelloy B
2 Hastelloy C
3 Titanium(Ti)
4 Tantalum (Ta)
5 Platinum(Pt)
Code Lining Material
0 No(Standard Type)
1 Polytetrafluoroethylene
2 Polyvinyl fluoride
3 Fluorinated ethylene-propylene
4 Polychloroprene rubber
5 Polyurethane
Code Max.Pressure
0 1.6Mpa for DN100~DN3000(Standard Type)
Code Output
A 4~20 mA (Standard Type)
P Scale Pulse Output
R RS-485 MODBUS Communication
C RS-232 Communication
H Hart Communication
Code Max Temperature
0 .~70 ℃(Standard Type)
Code Display Type
N Traditional Chinese(Standard Type)
S Simplified Chinese
I English
Code Connection Line
N Compact-type without cable(Standard Type)
Code Power Supply
N AC 85~265V 45~63Hz(Standard Type)
R DC 24
Code Logo
F FGT Logo(Standard Type)
N Printing customer Logo
FMG Complete Ordering Code
*Note: Using customer Logo launch to more than 100 united for one year
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