Electromagnetic Flowmeter

Electromagnetic Flowmeter

Product Details

I. Overview

The electromagnetic flowmeter is a product that performs flow measurement based on Faraday's law of electromagnetic induction. The flowmeter has high accuracy , minimal pressure loss, high reliability , and large measurable range. The ratio of the maximum flow to the minimum flow is generally 20:1 or more, and the industrial pipe diameter range is up to 3m. The output signal is linear with the measured flow rate, and can measure alkali, acid, salt solution, sewage with conductivity ≥5μs/cm. Corrosive liquids and fluid flows such as pulp, mud, pulp, etc.; flow measurements of pure water, steam, and gases are not possible. Electromagnetic flowmeters are widely used in medicine, food, chemical, electric power, metallurgy, papermaking and other industries.

Second, the working principle

When the conductor performs a cutting magnetic field motion in a magnetic field, an induced potential is generated, and the magnitude of the induced potential is proportional to the speed at which the conductor moves in the magnetic field perpendicular to the direction of the magnetic field and the effective length in the magnetic field. Similarly, when a conductive fluid flows in a vertical direction in a magnetic field and cuts an inductive force line, an induced potential is also generated on the electrodes on both sides of the tube. The direction of the induced potential is determined by the right-hand rule, and the magnitude of the induced potential is determined by:

Ex = BVD .................................. (1)

Where Ex - induced potential V;

B——magnetic induction intensity T;

D——the inner diameter m of the measuring tube;

V——the average flow velocity m/s of the cross section of the measuring tube;

However, the volume flow rate qv is equal to the product of the flow velocity V of the fluid and the cross-sectional area of the pipe (πD2) / 4, and the formula (1) is substituted into the formula:

QV = (πD/4B)*Ex .....................................(2)

It can be seen from the above formula that when the pipe diameter D has been determined and the magnetic induction intensity B is kept constant, the measured volume flow rate is linear with the induced potential. If an electrode is inserted on each side of the pipe, the induced potential Ex can be introduced, and the magnitude of the potential can be measured to obtain the volume flow. According to the Faraday electromagnetic induction principle, a pair of detecting electrodes are mounted on the wall of the tube perpendicular to the axis of the measuring tube and the magnetic line of force. When the conductive liquid moves along the axis of the measuring tube, the conductive liquid cuts the magnetic line to generate an induced potential, and the induced potential is detected by two detecting electrodes, and the magnitude is proportional to the flow rate, and the value is:


Where E is the induced potential;

K——a constant related to the distribution of the magnetic field and the axial length;

B——magnetic induction strength;

V——the average flow rate of the conductive liquid;

D——electrode spacing (measuring inner diameter)

The sensor transmits the induced potential E as a flow signal to the converter, and after being processed by amplification, conversion filtering, etc., the dot matrix liquid crystal with backlight is used to display the instantaneous flow rate and the accumulated flow rate. The converter is outputted by 4-20mA, alarm output and frequency output, and has RS-485 communication interface, and supports HART and MODBUS protocols.

Third, technical performance parameters

main power AC220V 50Hz / DC24V / 3.6V
Power consumption <15w (and="" sensor="" power="">
Damping time constant Continuous variables are available from 0 to 100s (90%) time binning
communication Optional RS232C or RS485 serial communication interface, HART communication protocol, with lightning protection
Loss of power The instrument is designed with a power-down clock and can store 16 power-down records (10 years)
Protection level IP65
Nominal diameter DN6mm~DN3000mm
Nominal pressure 0.6~4.0MPa (special pressure can be customized)
Accuracy ±0.5% of the indicated value, ±0.3% or ±0.2% of the optional value
Lining material Polychloroprene, urethane rubber, silicone rubber, polytetrafluoroethylene (PTEE), polyperfluoroethylene propylene (F46), PFA
Electrode form Standard type, scraper type, replaceable type
Electrode material SUS316, Hastelloy B, Hastelloy C, titanium, tantalum, platinum/rhenium alloy, stainless steel coated tungsten carbide
Medium temperature Integrated type -20°C~+70°C
Split type Polyfluorobutene lining/polyurethane lining -20°C~+60°C
PFA lining / F46 lining / silicone rubber lining -40°C~+160°C
Ambient temperature -25°C~+60°C
environment humidity 5~100% RH (relative humidity)
Dielectric conductivity ≥20μs/cm
Measuring range 1500:1 flow rate setting <15m>
structure type Integral, split, immersed, explosion-proof
Protection level IP65, IP67, IP68 optional
Explosion-proof mark ExmdIIcT4
Product Standards JB/T9248-1999 electromagnetic flowmeter

Fourth, the main performance of lining materials                                    

Lining material Main performance Scope of application

1, good wear resistance, excellent elasticity, high tearing force

2, resistant to general low concentration acid, alkali, salt medium corrosion, not resistant to oxidative medium corrosion

Water, sewage, weak abrasive mud, slurry temperature range: -20 ° C ~ +60 ° C
Polyurethane rubber

1, has excellent wear resistance (equivalent to 10 times the natural rubber)

2, acid and alkali resistance is poor

3, can not be used for water mixed with organic solvents

Neutral strong wear of pulp, coal slurry, mud and other temperature resistance range: -20 ° C ~ +60 ° C
Polysilicone rubber

1, has excellent elasticity, high tearing force, high temperature resistance

2, is not resistant to corrosion of any concentration of acid, alkali, salt medium

Water temperature range: -20 ° C ~ +180 ° C
Polytetrafluoroethylene (PTFE)

1. The most stable chemical material in plastics, resistant to boiling hydrochloric acid, sulfuric acid and aqua regia, and resistant to concentrated alkali and

Various organic solvents, not resistant to chlorine trifluoride, high flow rate liquid fluorine, liquid oxygen, ozone corrosion.

2, poor wear resistance

Temperature range of strong corrosive medium such as concentrated acid and alkali: -40°C~+120°C
Polytetrafluoroethylene propylene F46

1, corrosion resistance and PTEE

2, can withstand low wear

3, strong resistance to negative pressure

Same as PTEE, can be used for low wear type medium temperature range: -40 ° C ~ +160 ° C
PFA Corrosion resistance and PTEE, strong resistance to negative pressure Can be used in the negative pressure state temperature range: -40 ° C ~ +160 ° C


Five, electrode material corrosion resistance                              

Electrode material Corrosion resistance
SUS316 It is used in industrial water, domestic water, sewage, and weakly corrosive media. It is widely used in petroleum, chemical, steel and other industrial sectors as well as municipal and environmental protection.
Hastelloy B (HB) It has good corrosion resistance to hydrochloric acid at all concentrations below the boiling point, and is also resistant to corrosion by non-oxidizing acids, alkalis, and non-oxidized salt liquids such as sulfuric acid, phosphoric acid, hydrofluoric acid, and organic acids.
Hastelloy C (HC)

It is resistant to non-oxidizing acids such as nitric acid, mixed acid or corrosion of mixed media of chromic acid and sulfuric acid, as well as oxidation resistant salts such as Fe+++, Cu++ or other oxidants. If higher than

Corrosion of hypochlorite solution and seawater at room temperature.

Titanium (Ti)

It is resistant to seawater, various chlorides and hypochlorites, oxidizing acids (including fuming sulfuric acid), organic acids, alkalis, etc., and is not resistant to the corrosion of pure reducing acids (such as sulfuric acid and hydrochloric acid).

eclipse. However, if the acid contains an oxidizing agent (such as nitric acid, Fe+++, Cu++), the corrosion is greatly reduced.


It has excellent corrosion resistance and is very similar to glass. It can resist almost all chemical media except hydrofluoric acid, fuming sulfuric acid and alkali (including boiling point of hydrochloric acid, nitric acid and below 150 °C).

Corrosion of sulfuric acid and aqua regia). Note: It is not resistant to corrosion in alkali.

Platinum/niobium alloy It is suitable for almost all chemicals, but not for aqua regia and ammonium salts.
Stainless steel coated tungsten carbide For non-corrosive, strong abrasive media.

Sixth, shape and installation size


Nominal diameter (mm) Nominal pressure (Mpa) Dimensions Reference weight (kg)

Instrument length (lined)


6 4.0 200 90 220 6
10 200 90 220 6
15 200 95 220 8
20 200 105 220 10
25 200 115 223 12
32 200 140 240 13
40 200 150 250 14
50 200 165 263 15
65 1.6 250 185 283 18
80 250 200 290 20
100 250 235 318 25
125 250 270 350 28
150 300 300 380 30
200 350 340 430 50
250 450 405 495 70
300 1.0 500 460 547 95
350 550 520 602 120
400 600 580 665 140
450 600 640 720 160
500 600 715 783 200
600 600 840 897 280
700 700 895 982 350
800 800 1015 1092 400
900 900 1115 1192 480
1000 1000 1230 1299 550
1200 0.6 1200 1405 1488 660
1400 1400 1630 1700 750
1600 1600 1830 1924 850
1800 1800 2045 2134 980
2000 2000 2265 2344 1200
2200 2200 2475 2549 1600
2400 2400 2685 2754 2000
2600 2600 2905 2964 2400
2800 2800 2905 3169 2700
3000 3000 3315 3369 2900


Seven, selection table

1 Ground electrode
2 Matching flange

Import insurance



Electrode scraping

Knife mechanism

5 other

Nominal diameter


6 600
Nominal diameter
DN6-DN3000 three digits, 10 100
(mm) See nominal diameter coding table 13 15 150
Nominal pressure 0.6MPa 1 20 200
1.0MPa 2 25 250
1.6MPa 3 32 320
4.0MPa 4 40 400
other 5 50 500
Connection method Flange type a 65 650
Clamp type b 80 800
Hygienic type c 100 101
Lining material Polychloroprene 1 125 125
Polyurethane rubber 2 150 151
Polysilicone rubber 3 200 201
Polytetrafluoroethylene (PTFE) 4 250 251
Polytetrafluoroethylene (F46) 5 300 301
PFA 6 350 351
Electrode material Molybdenum-containing stainless steel (SUS316) 1 400 401
Hastelloy B (HB) 2 450 451
Hastelloy C (HC) 3 500 501
Titanium (Ti) 4 600 601
钽(Ta) 5 700 701
Platinum/niobium alloy 6 800 801
Stainless steel coated tungsten carbide 7 900 901
structure type Integrated type 1 1000 102
Split type 2 1200 122
Split immersion 3 1400 142
Integrated explosion-proof type 4 1600 162
power supply 220VAC 50Hz A 1800 182
24VDC D 2000 202
3.6V V 2200 222

Output /


Volume flow 4~20mADC/pulse A 2400 242
Volume flow 4~20mADC/RS232C serial communication interface B 2600 262
Volume flow 4~20mADC/RS485 serial communication interface C 2800 282
Volume flow HART protocol output / with communication D 3000 302





Customer Service Hotline:13938765366

Company Telephone:13938765366



Company Address:North Section of Yuanxin Road, Xinxiang City, Henan Province


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