EMC in English, meaning electromagnetic compatibility. It consists of the initials of Electromagnetic Compability. Electromagnetic compatibility tests are intended to ensure that any electrical system or device can operate or not be affected by other electrical systems and devices in its vicinity. All electrical and electronic devices generate a number of electromagnetic noise or waves during operation and emit them to the environment. This naturally affects the operation and performance of other devices.

Two basic requirements arise in electromagnetic compatibility tests:

• Any electrical system or device must be able to operate without being affected by other electrical systems and devices in the vicinity
• Any electrical system or device must not interfere with other electrical systems and devices while operating

In short, an electrical or electronic system or device must meet both of these basic conditions.

For the free movement of electrical or electronic products in the countries of the European Union, it must be certified that they comply with the specified norms. Within the scope of the CE certificate, the manufacturers have to undertake EMC tests for the devices they produce as well as the LVD tests. The EMC test reports are one of the basic documents of the technical file prepared within the scope of CE marking application.

During EMC tests, the electromagnetic noise emission (emission) values ​​emitted by the systems or devices from the air or cable are measured. At the same time, the extent to which these systems and devices are affected by the electromagnetic noise generated in their environment is measured (immunity measurements).

The variety and sensitivity levels of electrical and electronic systems and devices in use today are increasing every day, and EMC testing has become a necessity not only for CE marking but also for consumer satisfaction.

EMC tests are also performed within the scope of electrical tests carried out by accredited laboratories and many standards issued by national and international organizations are taken into consideration during these tests.

European harmonized standards were developed by the European Standardization Bodies (ESO), following a mandate from the European Commission. The EMC Directive also requires the publication of references to these standards in the OJEU for harmonization and, therefore, to ensure the assumption of conformity.

Anechoic RF chamber used for EMC testing (radiated emissions and immunity). Furniture should be made of wood or plastic, not metal.

Log-periodic antenna measurement for outdoor
Electromagnetic compatibility (EMC) is a branch of electrical engineering related to unwanted production, propagation and reception that can cause undesirable effects such as electromagnetic interference, even electromagnetic interference (EMI) or even physical damage to the operating equipment. The purpose of the EMC is the correct operation of different equipment in a common electromagnetic environment.

EMC follows three main subject classes. Emission is the deliberate or random production of electromagnetic energy by a source or its release into the environment. EMC examines unwanted emissions and countermeasures that can be taken to reduce unwanted emissions. The second class is the tendency of the so-called electrical equipment victim to malfunction or deterioration in the presence of unwanted emissions known as electrical frequency equipment (RFI). Immunity, in contrast to sensitivity, the ability of the equipment to function correctly in the presence of RFI, the discipline of the "curing" equipment, is known as equal sensitivity or immunity. It is a third-class link that is being studied, which is the mechanism by which the spreading intervention reaches the victims.

Noise reduction and consequently electromagnetic compatibility can be achieved by addressing any or some of these problems, ie, by silencing sources of interference, blocking interlocking pathways and / or hardening potential victims. In practice, many engineering techniques, such as grounding and shielding, apply to all three issues.