Principle and structure of electromagnetic flowmeter

The measurement principle of FE20 electromagnetic flowmeter is based on Faraday's law of electromagnetic induction: when the conductive liquid cuts the magnetic field line in the magnetic field, an induced potential is generated in the conductor,

The induced potential is E:


In the formula: K——–instrument constant

In the formula: B————magnetic induction intensity

In the formula: V————the average flow velocity in the section of the measuring tube

In the formula: D——– measure the inner diameter of the pipe section

When measuring the flow rate, the conductive liquid flows through the magnetic field perpendicular to the flow direction at a speed V, the flow of the conductive liquid induces a voltage proportional to the average flow rate, and the induced voltage signal directly contacts the liquid through two or more The sensor electrode is detected, and sent to the converter through the cable for intelligent processing to realize the display of the instantaneous flow of the fluid, the display of the accumulated flow, and the communication between the flow data and the control system. There are no moving and blocking parts in the measuring tube, so there is almost no pressure loss and high reliability.

FE20 Electromagnetic Flow Features…Advantages

●Electromagnetic flowmeter is an instrument for measuring volume flow, and the measurement results have nothing to do with physical parameters such as flow velocity distribution, flow pressure, temperature, density, viscosity, etc.;

There are no moving parts in the measuring tube, which is convenient for maintenance and management, so the service life of the sensor is long; there are no blocking parts, because there is no pressure loss;

The conductivity of the liquid to be measured can be as low as 5μS/cm, and with various lining materials, it can be used to measure the flow of various acids, alkalis, salt solutions, and mud, pulp, pulp and other media with high accuracy;

Usually ±0.5% ±0.2%;

●Because the induced voltage signal is formed in the whole space full of magnetic field, it is the average value of the pipe section, so the straight pipe section required by the sensor is short, generally 3D before and after 5D;

●On the sensor part, only the lining and electrodes are in contact with the liquid to be measured. As long as the electrodes and lining materials are selected reasonably, they can be resistant to corrosion and wear, ensuring long-term use;

●Bidirectional measurement system, which can measure forward flow and reverse flow;

●High-definition backlight LCD display, Chinese and English menu operation, easy to use, simple to operate, easy to learn and understand;

The converter has reliable performance, high precision, low power consumption, stable zero point, convenient parameter setting, LCD display, which can display parameters such as cumulative flow, flow rate, and flow percentage;

●Using 16-bit embedded microprocessor, fast operation, high precision, programmable frequency low-frequency rectangular wave excitation, improved measurement stability, low power consumption;

●Full digital processing, strong anti-interference ability, reliable measurement, high precision, flow measurement range up to 150:1;

●Ultra-low EMI switching power supply, using a wide range of power supply voltage changes, good EMC resistance;

●With digital communication signal output such as RS485, RS232, HART and Modbus.

FE20 Electromagnetic Flow Characteristics…Limitations

●Electromagnetic flowmeter cannot measure gas, steam and liquid containing a large amount of gas.

●Electromagnetic flowmeter can not be used to measure liquid medium with very low conductivity at present. The conductivity of the measured liquid medium cannot be lower than 5μS/cm, which is equivalent to the conductivity of distilled water. It is powerless for petroleum products or organic solvents.

●The insulating lining of the measuring tube is limited by the temperature, and the electromagnetic flowmeter cannot measure high temperature liquid, and it is suitable for the temperature of the measuring medium ≤180°C ●The measurement principle of the electromagnetic flowmeter is based on Faraday's law of electromagnetic induction, so it is easily affected by external electromagnetic interference sources .


The liquid medium used to measure electrical conductivity requires that the electrical conductivity should be greater than 5μs/cm (the electrical conductivity of tap water, raw water is about 100…5000μs/cm, which can be used to measure various acids, alkalis, salt solutions and mud, ore pulp, paper pulp It is mainly used in petrochemical, steel, electric power, metallurgy, textile, food, pharmaceutical, paper and other industries as well as municipal environmental protection, water conservancy and other fields .

technical parameter

Nominal diameter (mm)Pipeline PTFE lining: DN10~DN600
 Pipe type rubber lining: DN40~DN1200 (special specifications can be customized)
Flow direction:Positive, negative, net flow
Turndown ratio:150:1
Repeatability Error:±0.1% of measured value
Accuracy class:0.2% & 0.5%
Measured medium temperature:Ordinary rubber lining: -20~+60℃
High temperature rubber lining: -20~+90℃
PTFE lining: -30~+100℃
High temperature PTFE lining: -20~+180℃
Rated working pressure:
(high pressure can be customized)
DN80 - DN150 : ≤1.6MPa
Display unit:m³/H、m³/M、m³/S、L/H、L/M、L/S、G/H、G/M
G/S(H=Hour M=Minute S=Second)
Implementation standard:LVD 2006/95/EC&EMC 2004/108/EC
EN 61326-1::2006 Emission Standard (BS EN50081-1)
EN 61326-1::2006 Immunity Standard (BS EN50082-1)
EN 61010-1:2001 Equipment Safety Requirements: General Requirements
Velocity range:0.3-12m/s
Conductivity range:The conductivity of the measured fluid is greater than or equal to 5μs/cm
Current output:Load resistance: 0~10mA: 0~1.5KΩ; 4~20mA: 0~750KΩ
Digital frequency output:The upper limit of output frequency can be set within 1~5000Hz with photoelectric
Isolated transistor open collector bidirectional output. External power
The maximum collector current is 250mA when the source ≤ 35V is turned on.
Power supply:AC220V, DC24V or 3.6V lithium battery
Total power consumption:less than 20W
Connection method:Flange, clamp connection and threaded connection can be used between flowmeter and piping
environment humidity:<90%rh (non-condensing)
Protection class:IP65 (special order IP68)
Ambient temperature:-25~+60℃ (please consult an engineer under special conditions)
Required straight pipe length:Upstream≥5DN, downstream≥3DN
Implementation standard:DIN EN 1092-1-2002
Standard of the place of use for sales (Order remarks)
Electrical connection method:M20*1.5

Selection table

FE20-Electromagnetic Flowmeter
 Applicable media
 General purpose medium
 Slurry measurement type
 Transmitter Mounting Type
 All-in-one display setting type
 Split remote display setting type (round)
 Split remote display setting type (square)
 The way to
 6 to 2800mm (such as pipe diameter DN10 and expressed as 10)
 Installation method
 Flange type (DN10 to DN2800)
 Wafer type (DN25 to DN150)
 Threaded type (DN10 to DN50)
 Sanitary clamp type (DN15 to DN80)
 Electrode material
 Electrode material stainless steel 1.4435 (316L)
 Electrode material Ti (titanium)
 Electrode material Ta (tantalum)
 Electrode material Wolfram Carbide (tungsten carbide)
 Electrode material Pt platinum
 Electrode material Ni nickel
 Electrode material Hastelloy HC
 Electrode material Hastelloy HB
 Special material form customization
 Housing and flange material
 Main body material: carbon steel
 Main body material: stainless steel 1.4301 (304)
 Main body material: stainless steel 1.4435 (316L)
 output method
 no output
 4 to 20mA+pulse
 4 to 20mA+pulse+high and low flow double point alarm
 Lining material
 Lining material CR (Neoprene)
 Lining material PTFE (polytetrafluoroethylene)
 Lining material F46 (polyperfluoroethylene propylene)
 Lining material FEP (fluorinated ethylene propylene copolymer)
 Lining material PFA (perfluoroalkoxy resin) Teflon
 Lining material PUR (polyurethane rubber)
 Power supply
 DC 18V to 38V
 AC 85V to 265V
 Battery power supply
 Accuracy class
 (Optional accessory) Grounding method
 no ground ring
 Stainless steel 1.4435 (316L) grounding ring
 Titanium alloy grounding ring
 Explosion proof type
 Normal type without explosion-proof function
 Explosion-proof functional type
This PDF does not contain the complete data of the selection table. For selection, please contact the sales staff or email to to obtain the complete sample
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