What Is a Simple Way to Detect EMI?

By Stephanie Hancock

EMI, or electromagnetic interference, can cause disruption with electronic items in your household, such as your cell phone, radio, television, satellite and computer. Conducted current, voltage, and radiated electromagnetic fields cause EMI. Detecting EMI can help you determine the safety of an electronic device. EMI detection can save the life of someone with a pacemaker. EMI interferes with the rhythm of the heart produced by the pacemaker.

Step 1

Tune an AM radio to a low frequency that does not bring in an audible radio station.

Step 2

A cell phone can help you understand what to listen for to detect EMI.

Turn on your cell phone or cordless phone and place a phone call. Hold the phone near the AM radio and pull it away. You will hear a difference in the standard interference noise when you move the phone closer to the device. This will help you understand what to listen for.

Step 3

A television antenna can cause EMI.

Find the area in which you think EMI happens. Check areas near communication or other electronic devices that rely on waveforms of information to work, such as a satellite television or wireless Internet. Put your AM radio near the source of the potential EMI.

Listen for interference that sounds like a pulsating change in the regular "snow" or white noise. You may hear bleeps or blips, people speaking or loud buzzing. If there is no EMI, you will hear no difference in the white noise.

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