Electromagnetic water flow meter

Electromagnetic water flow meter overveiw

Electromagnetic water flowmeter is a flow measurement instrument made by Faraday's law of electromagnetic induction to measure the volume flow of conductive water.
In 1922, Williams EJ (WlamsE.J) first applied electromagnetic flow instruments to closed circular tubes; in 1937, Colin A. (Kolin A.) successfully measured blood vessel flow by mag flowmeter; in the early 1950s, EMF realized industrial application, the Netherlands Tobi Company (Predecessor of Alto meter) It first launched products for process industry and became a new generation of flow meters that entered mature applications earlier. In recent years, the worldwide production of EMF accounts for about 5% to 6.5% of the number of industrial flow instruments. In 1994, first electromagnetic water flow meter factory established and produce 95,000 to 125,000 nos magnetic flow meters. 
 

Electromagnetic flow meter for water

In many industries, such as Petrochemical, iron and steel metallurgy, water supply and drainage, water conservancy irrigation, water treatment, environmental protection sewage measurement and control, papermaking, medicine, food and other industrial and agricultural production processes, many kinds water flow meter needed, such as Salt water flow meter, desalinated water flow meter, ammonia water flow meter, sea water flow meter, purified water flow meter, drinking water, tap water, waste water flow meter, sewage, effluent water flow meter, sanitary water flow meter, acid water flow meter, alkaline water, well water, ground water flow meter,  surface water, condensate water, fire water flow meter, cement slurry, mineral water , hydrogen peroxide, hard water, soft water, bottle water flow meter;
Electromagnetic flow meter can measure water flow rate and calculate total water which water is with conductivity.
 

Electromagnetic flow meter working principle

The basic principle of electromagnetic water flow meter is Faraday's law of electromagnetic induction, that is, when a conductor moves in a magnetic field, an induced electromotive force is generated at its two ends. , the conductive water flows in the non-magnetic measuring tube perpendicular to the magnetic field, and an induced potential proportional to the water flow is generated in the direction perpendicular to the flow direction. Magnetic water flow meter is composed of flow sensor and magnetic water flow converter. There are excitation coils on the top and bottom of the measuring tube. After passing the exciting current, a magnetic field is generated and passes through the measuring tube. A pair of electrodes is installed on the inner wall of the measuring tube to contact with water, and the induced potential is drawn out and sent to the converter. The excitation current is provided by the converter.
 

Advantage of electromagnetic water flow meter

• The measuring channel of electronic water flow sensor is a smooth straight pipe with no obstruction flow detection element, which is not easy to block and is suitable for measuring liquid-solid two-phase fluids containing solid particles or fibers, such as pulp, coal-water slurry, waste water and sewage.
• Mag meters for water do not produce pressure loss due to flow detection. It is most suitable for large size water supply pipelines that require low resistance loss, such as DN200 water flow meter, 10” dial size water flow meter, 12 inch digital water flow meter;
• The volume flow measured by EMF is not significantly affected by slow changes in fluid water density, viscosity, temperature, pressure and conductivity.
• Compared with most other water flow meters, the requirements for the straight pipe section are also lower.
• The mag meters for water measurement range is large, usually 20:1~50:1, and the optional flow range is wide. The water flow velocity can be selected within 0.5~10m/s.
• Electromagnetic water flow meter has a lot options for water flow sensor ,from micro flow sensor 3mm to 30000 mm, normal request include 3/8” ,1/4” micro water flow meter,1/2 inch magnetic water flow meter, 1 inch, 2 inch magnetic water ,6 inch, 8”,10.,etc
• Electromagnetic water flow meter can measure forward and reverse bidirectional water flow, and also measure pulsating water flow;
• Magnetic water flow meter output is linear output 4-20Ma; it is electronic water flow meter;
• Magnetic flow meter is easy to select the material variety of the parts in contact with different kinds water , which can be applied to corrosive water , dirty water or clean water;
• Low price electromagnetic water flow meter, price starts from $ 400

Disadvantages of electromagnetic water flow meter

• EMF cannot measure water with very low conductivity, such as petroleum products and organic solvents, RO water, pure water.etc
• Gases, vapors and waste water with many larger bubbles cannot be measured.
• General-purpose EMF cannot be used for higher temperature water due to the limitation of lining materials and electrical insulation materials; some models of instruments are used for liquids, such as frozen water below room temperature, and the insulation is damaged due to condensation (or frost) outside the measuring tube.

Technical Specifications of electromagnetic water flow meter

• Mater sensor size: Applicable pipe diameter: from 3mm to 3000mm,from micro water flow meter to large pipeline water flow meter
• Electrode material: 316L (stainless steel), HC (Hastelloy C), HB (Hastelloy B), Ti (titanium), Ta (tantalum)
• Applicable water with conductivity >5us/cm
• Measuring water range 0.1~10m/s
• Electromagnetic water flow meter Accuracy: class 0.3, 0.5, 1.0
• Electronic water flow meter Output signal 4~20mADC, load ≤750Ω; 0~3 KHz, 5V active, variable pulse width, high-end effective frequency output: RS485 interface, PROFIBUS-DP, HART Protocol;
• Working pressure 1.0MPa, PN16,PN40 , 16MPa (special), 150LB, 300#, 600 pounds,ANSI, ASME,JIS,DIN;
• Fluid temperature -20°C~80°C, 80°C~130°C, 130°C~180°C;
• Ambient temperature : -40°C~80°C; converter -15°C~50°C
• Ambient temperature ≤85RH (at 20°C)
• Power supply 220VAC±10%; 50Hz±1Hz; 24VDC±10% or battery operated magnetic water flow meter;
• Power consumption ≤8W
• Protection Level for magnetic water flow meter: IP65, IP68
• Magnetic water flow meter shell material: carbon steel, SUS 304 or SUS 316;