The Difference Between EMI and EMC

The Difference Between EMI and EMC

In today’s world, electronic devices and equipment need to be tested for EMI and EMC before being brought to market. But do you know the difference between the two? While they’re related, knowing the difference between EMI and EMC is important for a successful product.

EMI (Electromagnetic Interference)

EMI is released energy. More specifically, EMI—electromagnetic interference—is energy (or radiation) released from an electrical device that disrupts other electrical devices.

While every electronic will have energy contained by plastic, rubber or metallic casings, some of that energy will escape. These waves of radiation travel through the air and, when they meet other electronics, may affect how well other devices works.

For example, if a power drill is running in one room, the TV in the next room may not be able to work as well. The picture may fade or the sound might not come through all the way.

This is why most electronic devices have some type of shielding or lining built in that contains as much radiation as possible to reduce EMI in other products.

Sources of EMI

EMI can come from both natural and manmade sources. The earth produces lightning and the sun produces solar radiation, both of which can affect how well electronics work.

Almost all electronics can cause EMI, including:

  • Cellphones
  • Motors and generators
  • Microwaves
  • AM and FM radios
  • Baby monitors
  • X-ray and MRI machines

EMC (Electromagnetic Compatibility)

EMC is how well a device blocks EMI. More specifically, EMC—electromagnetic compatibility—measures how well electrical devices can function while being hit with EMI (released energy from another electrical device).

While EMI is the problem, EMC sees how a well that problem can be handled. To combat EMI, electronic devices will have EMI shielding made of materials like metals, rubbers and fabrics.

Nearly any electronic device can be interrupted by EMI and need to be tested for EMC. Testing for electromagnetic compatibility is especially important in products like pacemakers and hard drives, where life and vital data are at risk.

EMI, EMC and Your Product

When prototyping and choosing materials for your product, you need to make sure you both don’t emit an excess of EMI and that your product can function in the presence of EMI from other devices.

Need help? Give us a call. Our materials engineers can walk you through the process and help you choose the best EMI (or RFI) shielding.

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