Electromagnetic compatibility

Electromagnetic compatibility (EMC) is the ability of electrical equipment and systems to function acceptably in their electromagnetic environment, by limiting generation, propagation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage to operational equipment. The primary goal of EMC is the correct operation of equipment in a common electromagnetic environment. An EMC engineer, an associated discipline within the electrical engineering, pursues mitigating EMI, resulting in improved electromagnetic compatibility, in products by focusing on three main EMC hazard classes: Emission is the generation of electromagnetic energy, whether deliberate or accidental, from a source and its release into the environment. This hazard class can be mitigated by quieting the sources of interference. Susceptibility is the tendency of electrical equipment, referred to as the victim, to malfunction or break down in the presence of emissions, also collectively known as radio-frequency interference (RFI). Immunity is the opposite of susceptibility, being the ability of equipment to function correctly in the presence of RFI, with the discipline of "hardening" equipment focusing on reducing susceptibility or immunity. Coupling is the mechanism by which emitted interference reaches the victim. This hazard can be mitigated by inhibiting coupling paths. EMI in practice is typically mitigated by using broad based approaches that may impact all three hazard classes, such as grounding and shielding. After the unit is built, various EMS test standards may need to be met before entering the unit for sale into a country's market.