Instrument Mesurement Knowledge

What is an Electromagnetic Flowmeter?

Views: 141     Author: Site Editor     Publish Time: 2024-07-09      Origin: Site

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A magnetic flow meter (mag meter, electromagnetic flow meter) is a transducer that measures fluid flow by the voltage induced across the liquid by its flow through a magnetic field. A magnetic field is applied to the metering tube, which results in a potential difference proportional to the flow velocity perpendicular to the flux lines. The physical principle at work is electromagnetic induction. The magnetic flow meter requires a conducting fluid, for example, water that contains ions, and an electrical insulating pipe surface, for example, a rubber-lined steel tube.

If the magnetic field direction were constant, electrochemical and other effects at the electrodes would make the potential difference difficult to distinguish from the fluid flow induced potential difference. To show this in modern magnetic flowmeters, the magnetic field is constantly reversed, cancelling out the electrochemical potential difference, which does not change direction with the magnetic field. This however prevents the use of permanent magnets for magnetic flowmeters.

Measuring Principle

Faraday's law of induction states that a metal rod moving in a magnetic field induces electrical voltage. This dynamo principle also governs the way electromagnetic flowmeters work.

Measuring Principle

As soon as the electrically charged particles of a fluid cross the artificial magnetic field generated by two field coils, an electric voltage is induced. This voltage, tapped by two measuring electrodes, is directly proportional to the velocity of flow and thus to the flow volume.

The magnetic field is generated by a pulsed direct current with alternating polarity. This ensures a stable zero point and makes the flow measurement insensitive to multiphase or inhomogeneous liquids, as well as low conductivity.


  • The measuring principle is virtually independent of pressure, density, temperature and viscosity

  • Even fluids with entrained solids can be metered, e.g. ore slurry or cellulose pulp

  • Wide range of nominal diameters (DN 2 to 3000; 1/12 to 120")

  • Free pipe cross-section: CIP/SIP cleanable, piggable

  • No moving parts, maintenance-free


There are a number of applications of electromagnetic flowmeters in the Artang range. The Type Aimag S version with a stainless steel sensor can be used in applications with high pressures of up to PN16 and high temperatures of up to 150°C. Furthermore, the Type Aimag C with Alloy C22 electrodes has been designed for applications with aggressive fluids (chemicals) and especially sea water applications.

Electromagnetic Flow Meter

Whereas, Type Aimag A/Aimag D full bore mag flowmeters are designed for water treatment and general purpose applications. Combined with an actuated valve, the complete full bore mag flowmeter Type Aimag H can control high-precision dosing operations and flow measurement in food and beverage or pharmaceutical applications, which is suited to Clean in Place (CIP) applications. 

ARTang Electromagnetic Flow Meter

Insertion type electromagnetic flowmeter

Insertion type electromagnetic flowmeter is a reliable measuring instrument for liquid flow measurement in large and medium caliber pipes (DN25-DN3000mm). Meet the needs of many different applications. Flow rate measurement range: 0.1m/s-15 m/s, protection grade: IP68, for pipeline electromagnetic flowmeter in the large pipeline installation difficulties, costs and other defects.

Sanitary electromagnetic flowmeter

Sanitary electromagnetic flowmeter adopts a new type of sanitary lining materials and lining process, in line with the hygiene requirements of the food industry, while the use of stainless steel shell and stainless steel clamp connection, easy to electromagnetic flowmeter rapid disassembly, cleaning, so that the electromagnetic flowmeter is not easy to be contaminated in the process of use, and can effectively prevent the measurement of the fluid residue in the measurement pipe accumulation.

Electromagnetic flowmeter installation guide:

1. Horizontal and vertical installation: the sensor can be installed horizontally and vertically, but should ensure that to avoid the impact of sediment and air bubbles on the measuring electrode, the electrode axial to maintain the level is good. Vertical installation, the fluid should flow from bottom to top. The sensor can not be installed in the highest position of the pipe, this position is easy to accumulate air bubbles.

2. Ensure full pipe installation: ensure that the flow sensor in the measurement, the pipe is full of the measured fluid, can not appear non-full pipe state.

3. The sensor can not be installed in the inlet of the pump: To avoid negative pressure, the sensor can not be installed in the inlet of the pump, but should be installed in the outlet of the pump.

4. Inlet straight pipe section and outlet straight pipe section: the more ideal installation location should be selected before and after the measurement point has enough straight pipe section. Import straight section should be ≥ 10 × DN, export straight section ≥ 5 × DN.

5. Grounding: electromagnetic flowmeter must be properly grounded in order to eliminate electromagnetic noise and ensure the safety performance of the instrument.

6. Installation environment requirements: should ensure that the installation site around no vibration, no strong electromagnetic field.

If you would like any more information about our Electromagnetic Flowmeters please contact us.

ARTANG flowmeter


Hangzhou City, Zhejiang

About ARTang

ARTang is a global leader in measurement instrumentation, services and solutions for industrial process engineering that energizes the transformation of society and industry to achieve a more productive, sustainable future. We provide process solutions for flow, level, pressure, analytics and digital communications, optimizing processes in terms of economic efficiency, safety & environmental impact.


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