Electromagnetic Flow Meters

Science / Monday, November 20th, 2017

A couple of weeks ago, we looked at what spray foam insulation is and how it works. This week, we’re covering an even less known topic: flow meters. More specifically, electromagnetic flow meters. You won’t find these lying around your house, instead, you would come across them in industry environments, such as factories. Flowquip brings you this interesting and informative article on what flow meters are and how an electromagnetic flow meter works.

What are flow meters?

Flow meters are used in industries as a way to measure the movement of whatever material they use in their processes. For instance, you can get flow meters that measure oil, water, gas, food, petrochemicals and loads of other substances. If you’re working with any of these, then you’ll want to know how much of them is going into your process or coming out as your product. Flow meters therefore help keep you in control of whatever work your factory or industry undergoes.

Types of flow meter

As there are loads of different kinds of materials that need controlling, from water to gas, there are also loads of different flow meters to measure them. Every flow meter works in a different way so that it can correctly measure the right substance. Some kinds of flow meters, wouldn’t be able to measure water, for instance due to the way they work. Some flow meters also wouldn’t be appropriate because they have to penetrate a pipe in order to measure the substance. If interruption to flow is impossible, then this kind of meter can’t be used. If the substance is dangerous, then penetrating the pipe in order to install the flow meter could be an impossibility. This is why there are so many.

To name some of the options, there are: coriolis flow meters, ultrasonic, turbine, air flow and electromagnetic meters. We’re going to look in more detail about how an electromagnetic flow meter works.

Electromagnetic fields and Ions

Electromagnetic flow meters are usually used to measure liquids, although they can also measure gases. Whatever the substance, it must be one with ions. Ions are electrically charged particles and can be negative or positive, formed when atoms gain or lose electrons. Water, for instance, is full of ions because the atoms exchange and swap around electrons when water is created.

The electromagnetic flow meter relies on these ions.

The meter is attached to a pipe and, once activated, it creates an electromagnetic field around the pipe. It constantly monitors this electromagnetic field and is able to detect small movement, irregularities and disturbances within it. As the substance, for instance, water, moves through the pipe, all the electrically charged ions that are present in it interact with the meter’s magnetic field. The flow meter uses this information to work out how much water has just moved through it. Because it knows the diameter of the pipe, it can calculate the volume of water.

This allows a flow meter to give any industry greater control over their processes.

Electromagnetic flow meters also have the benefit of not needed to penetrate the pipe in order to successfully measure the substance. This means that they’re perfect for industries dealing with dangerous chemicals. Or those that cannot interrupt the system without causing serious damage and loss.


If you want to know more about flow meters, you can visit Flowquip’s website or get in touch with them.