Views: 24 Author: Site Editor Publish Time: 2022-05-09 Origin: Site
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.
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.
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
Applications
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.
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.
If you would like any more information about our Electromagnetic Flowmeters please contact us.
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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