What Is Electromagnetic Compatibility?

Electromagnetic compatibility is an important aspect of global product safety testing. Electronic devices that give off radiation play increasingly vital roles in the lives of people around the world. Electromagnetic compatibility testing ensures that such devices can withstand the emission of electromagnetic radiation given off by other electronics in the vicinity while not affecting the operation of other products with excessive electromagnetic interference.

Issues Pursued by EMC Testing

The deliberate or accidental generation of electromagnetic energy is called emission. Unwanted emissions are referred to as radiofrequency interference. If a particular piece of electrical equipment has a tendency to break down or malfunction in the presence of radio frequency interference, it is referred to as the victim. The mechanism by which RFI reaches the victim is called coupling. The ability to withstand the effects of RFI is called immunity, while the tendency to break down in the presence of unwanted emissions is called susceptibility.

Ways To Make Equipment Electromagnetically Compatible

Electromagnetic compatibility can be achieved in one of three ways:

  • Hardening potential victims, i.e., increasing their immunity
  • Inhibiting the path of coupling between the RFI and the victim
  • Quieting the sources of interference

Engineering techniques such as shielding or grounding may be employed to address all three issues. Once the victim is no longer susceptible to RFI and can function in the presence of unwanted emissions, it can be said to be electromagnetically compatible.

International Electromagnetic Compatibility

Several countries have laws in place requiring that radiation-emitting products meet international standards for electromagnetic compatibility, as well as agencies to enforce those laws. In the United States, the main regulatory body for electromagnetic compatibility is the Federal Communications Commission.

Products Affected by Electromagnetic Compatibility

EMC testing is carried out on a wide range of products:

  • Medical equipment
  • Communication devices
  • Road traffic signals
  • Broadcast receivers
  • Toys
  • Tools
  • Household appliances
  • Electrical lighting equipment

Susceptibility of devices such as these to radiofrequency interference could range from a minor inconvenience to a life-threatening situation. That is why the international community places such a strong emphasis on electromagnetic compatibility.