Electromagnetic Flowmeters

What Is The Working Principle Of Electromagnetic Flowmeters?

• The working principle of electromagnetic flow transmitter is based on Faraday’s Law of Electromagnetic Induction. According to Faraday’s Law, when a conductor moves through a magnetic field, an electric voltage is induced across the conductor, perpendicular to both the direction of the magnetic field and the direction of movement.

• In the context of an electromagnetic flow meter, the liquid or fluid being measured acts as the conductor. The flowmeter generates a magnetic field across the pipe through which the fluid flows. As the fluid moves through this magnetic field, an electric voltage is induced. This voltage is directly proportional to the velocity of the flowing fluid.

• Electrodes placed on the walls of the pipe perpendicular to the direction of the magnetic field and the flow of the fluid pick up this induced voltage. The faster the fluid flows, the higher the voltage that is induced. By measuring this voltage, the flowmeter can calculate the flow rate of the fluid.

• Since the induced voltage is proportional to the flow velocity, and the flow area is known (based on the diameter of the pipe), the flowmeter can determine the volumetric flow rate of the fluid. This principle allows electromagnetic flow meter to measure the flow rate of any conductive liquid or slurry, including those with particulates, making them highly versatile for various industrial applications.

• It’s important to note that for accurate measurement, the fluid must have a minimum level of electrical conductivity, and the pipe must be full of fluid during measurement. Electromagnetic flowmeters are widely used because they have no moving parts, require minimal maintenance, and can measure the flow of corrosive, abrasive, and dirty fluids without being affected by changes in temperature, pressure, viscosity, or density.