Electromagnetic flow meters are also called as mag flow or mag meter because they are economic, obstruction less and suitable for aggressive chemicals and slurries and provide extremely accurate volumetric flow measurement.

1. Working of an Electromagnetic
Flow meter

2. Introduction
 Electromagnetic flow meters are also called as mag flow or mag meter.
 They are economic, obstruction less and suitable for aggressive chemicals and
slurries
 They provide extremely accurate volumetric flow measurement.
 Mag meters detect flow by using Faraday’s Law of induction.

3. Composition and Bases
 Inside an electromagnetic flow meter, there is an electromagnetic coil which
generates a magnetic field, and electrodes which capture electromotive force also
known as voltage.
 Because of this, even though it may appear as if there is nothing inside the flow
pipe of an electromagnetic flow meter, flow can be measured.
 The bases of these meters are derived from Faraday’s Law Of Induction.

4.  The potential difference proportional to the flow velocity perpendicular to the
flux lines is the result of a magnetic field is applied to the metering tube.
 It is defined as E=k*B*D*V mathematically and the physical principle at work is
electromagnetic induction.

5. Working of a flow meter
 The induced voltage is directly proportional to the velocity of the fluid moving
through the magnetic field.
 The electrode circuit is used to carry the induced voltage to the transmitter. The
voltage is converted into a quantifiable flow velocity using the transmitter.
 Using the known velocity along with the area of the pipe, the volumetric flow
rate of the fluid is calculated.
 Magnetic flow meters can measure fluids bi-directionally and are effective for
both very low and high-volume flow rates.

6.  Operations begin with a pair of charged magnetic coils When a flowmeter is
installed and activated.
 They produce a magnetic field that remains perpendicular to both the conductive
fluid being measured
 The axis of the electrodes taking measurements as energy passes through the
coils.
 Any generated induced voltage perpendicular to the field and the fluid velocity is
due to the fluid which moves along the longitudinal axis of the flowmeter.

7. Design of an electromagnetic flow meter

8. Advantages and Disadvantages
Advantages
 Capable to detect liquids that consist of contaminants.
 Moving parts are not present so this improves reliability.
 No pressure loss is found.
 Temperature, pressure, density, or viscosity of the liquid does not have any effect.
Disadvantages
 There is a requirement of a short section of straight pipe.
 Gases and liquids cannot be detected without electrical conductivity.