Home WORLD How to Measure Flow with Magnets – Magnetic Flow Meters

How to Measure Flow with Magnets – Magnetic Flow Meters

What happens when a civil engineer mixes water and electricity? The results aren’t always ideal, but you always learn something!

source/image: Practical Engineering

A magnetic flow meter relies on Faraday’s Law of Induction to measure the flow of a fluid. Magnets outside the pipe create a magnetic field. Electrodes are located perpendicular to the magnets.

A conductive fluid moving through the pipe will generate a voltage (electromotive force) between the electrodes due to Faraday’s law. The faster the fluid moves through the pipe, the higher the voltage.

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Once you know the velocity of the fluid, you can calculate flow using the cross sectional area of the pipe. In this video, I walk through some of the details that electrical engineers have worked out so that this ingenious device can work properly. Unfortunately I couldn’t get it working very well myself!