Electromagnetic Flow Meters: Functionality, Advantages, and Applications

Electromagnetic flowmeters are perfect for measuring the flow rate of any conductive liquid. These meters are extremely accurate and provide reliable flow measurements.

Working Principle of Electromagnetic Flow Meter

The functioning principle of the electromagnetic flow meter is based on Faraday’s Law of magnetic induction defined as follows:

E= k x B x D x V

The signal voltage (E) produced across any conductor moving at right angles across a magnetic field (B) is proportional to its velocity (V).

Two diametrically opposed, internally mounted measuring electrodes measure the voltage induced within the fluid.

The induced voltage generated by the magnetic coils is proportional to product of magnetic flux density, electrode distance (D), and fluid flow velocity (avg).

Construction of Electromagnetic Flow Meter

A common electromagnetic flowmeter includes a pipe through which conductive fluid flows and two electrodes positioned on opposing sides of the pipe.

Coils or permanent magnets generate a magnetic field that is perpendicular to flow direction. When the fluid passes through this magnetic field, a voltage is generated across the electrodes.

Measurement of Electromagnetic Flow Meter

The induced voltage is proportional to the flow rate of fluid.

The flowmeter measures this voltage, and the flow rate may be correctly calculated using the fluid’s properties and the pipe’s design.

Advantages of Electromagnetic Flow Meter

Electromagnetic flowmeters have various advantages, including the ability to measure flow rates of extremely conductive liquids (which include water & acids), excellent accuracy throughout a wide range of flow rates, low pressure drop, and resistance to corrosion and wear.

Disadvantages of Electromagnetic Flow Meter

  • Although electromagnetic flowmeters are extremely accurate and reliable, they have several limits.
  • They cannot measure non-conductive fluids (such as oils), & the fluid under test must have a minimum conductivity to generate a quantifiable voltage.
  • Furthermore, they are susceptible to flow profile aberrations and necessitate adequate installation & calibration for accurate observations.

Applications of Electromagnetic Flow Meter

  • They find use in a variety of industries, including water & wastewater management, chemical processing, food & beverage production, medicines, and more.
  • They are especially useful in applications where accurate & dependable flow measurement is required.