Electromagnetic Flow Meters (mag meters) | McCrometer
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Electromagnetic Flow Meters

Get Reliable Flow Measurement from our Mag Flow Meters

Electromagnetic flow meters (also called mag meters or magnetic meters), are volumetric flow meters which do not have any moving parts to wear, reducing the need for maintenance or replacement. Our mag meters have an accuracy over a wide flow range can be as good as ± 0.5% of flow rate or better.

McCrometer has over 65 years’ experience in flow measurement and is a global leader in electromagnetic flow meters. We are committed to innovative solutions and the highest possible quality in flow instrumentation.

We offer a range of full bore and insertion-style electromagnetic meters - suitable for agriculture, municipal, industrial, and even oil and gas applications.

Mag meters are commonly used for water-based liquids, but some models can also measure mixed media like slurries and sludge.

Our Mag Meters are Known for:

  • Durability: Our electromagnetic meters come with a variety of warranties, because they’ve been tested to the industry’s highest standards.
  • Innovation: McCrometer has been developing solutions for our customers and improving flow meters since 1955.
  • Quality: McCrometer is a global specialist. We design, manufacture, install, and test all of our own flow meters.

How do Electromagnetic Flow Meters Work?

Mag meters operate under the principle of Faraday’s Law of Electromagnetic Induction to measure liquid velocity. The principle of operation states that a conductor moving through a magnetic field produces an electric signal within the conductor, which is directly proportional to the velocity of the water moving through the field.

As fluid flows through the magnetic field, conductive particles in the fluid create changes in voltage across the magnetic field. This variation is used to measure and calculate the velocity of water flow through the pipe.


Mag Meter Product Suite

Our goal is to be our customers’ advisor and partner from project inception to ongoing metering champion.


Insertion Mag Meters

Insertion mag meters can be installed with an easy hot-tap process that does not disrupt flow or production.

FPI Mag®

The FPI Mag is the full-profile insertion mag meter ideal for new and retrofit projects. The FPI Mag’s hot-tap installation eliminates the need to interrupt service, de-watering lines, or cutting pipe, ideal for retrofits and tough applications.

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SPI Mag®

The single-point insertion SPI Mag is the cost-effective, accurate mag meter ideal for slurries, sludge, potable water, pulp stock, and more. Unlike conventional magnetic meters, the SPI Mag's cost is independent of pipe size.

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Saddle Mount Mag Meters

McCrometer’s unique saddle mount mag meters provide all the benefits of mag meters with the simplest possible installation. These flow meters have been especially designed for agricultural use cases.

Mc®Mag 3000

The McMag 3000 mag meter features robust construction and an angled sensor that sheds debris, making it ideal for use in surface water, dairy lagoons, and other dirty water applications.

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Mc®Mag 2000

The McMag 2000 retrofits using the Mc®Propeller saddle and offers Pulse output for system integration. Offering a 5-year full warranty, easy installation, and in-field maintenance, the McMag 2000 is the only mag meter on the market that maintains accuracy with flow straighteners!

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Flanged Flow Meters

Designed for the specific needs of the industrial, water, and wastewater industries, flanged flow meters also have wafer style configurations to meet installation specifications.

Dura Mag®

Requiring only 2D upstream and 1D downstream straight-run, the Dura Mag offers a 5-year meter and battery warranty, and lifetime liner guarantee. Its fusion-bonded epoxy coating eliminates risk of liner separation and water intrusion.

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Ultra Mag®

The Ultra Mag features an NSF-approved fusion-bonded epoxy UltraLiner™ and a lifetime liner guarantee, eliminating the risk of delamination and liner separation, and is ideal for applications near pumps, water wells, and other municipal locations.

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Mag Meter FAQs

Our specialists and customer service team members are happy to answer any questions you may have. In the meantime, here are a few we answer a lot.


What industries are best suited for electromagnetic flow meters?

Magnetic flow meters can work in almost any water-based use case, but they provide special value in a few specific industries:

  • Agriculture : Mag meters are a favorite in agriculture, especially for irrigation purposes. The fact that they include no moving parts means they work reliably in the field with no oversight or preventive maintenance needed.
  • Wastewater : Where debris can hinder and damage other types of meters, electromagnetic meters actually require some sediment and particulates, making them ideal for wastewater solutions.
  • Drinking water : Flow meters involved in municipal drinking water facilities need to earn NSF-61 certification to ensure their safety. Mag meters, like the Dura Mag and Ultra Mag flanged flow meters, can meet these requirements.
  • Cooling water : Cooling towers require +0.5% accuracy, low-maintenance solutions. Electromagnetic meters can meet these requirements and can also be installed without interrupting service.
  • Industrial : Electromagnetic meters are great for other industrial settings too, as they often qualify for Class 1, Division 2 classifications for hazardous areas.

What else do I need to know about electromagnetic flow meters?

It’s easy to see why mag meters are a lot of engineers’ favorite flow meters, but they’re not perfect for every setting. Electromagnetic meters are best suited for fluids with a conductivity that is 20 ohm/cm or higher. That means they’re not the best for:

  • Low velocity applications
  • Petroleum-based fluids, like oil

What is the accuracy of McCrometer mag meters?

Depending upon the product, it may vary. Our Ultra Mag and our FPI Mag offer up to ±0.5%. Our Dura Mag offers up to ±1%, and our SPI Mag, McMag 3000 and McMag 2000 offer up to ±2%. With extra calibration, the McMag 3000 can provide up to ±1% accuracy.

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Magnetic Flow Meter