The EMC Directive states that the electric and electronic apparatus shall be so constructed that :

• The electromagnetic disturbance it generates does not exceed a level allowing radio and telecommunications equipment and other apparatus to operate as intended.
• The apparatus has an adequate level of intrinsic immunity to electromagnetic disturbance to enable it to operate as intended.

These are general requirements which apply to all products as concerned with a view to controlling all EMC risks

The protection requirements of the EMC directive are laid down in terms of objectives, while the limit values and methods of measurements must be given in the harmonised standards.

To allow a systematic approach to the development of a harmonised standard for the implementation of the EMC Directive the standardisation bodies (CENELEC, IEC) have established a classification of electromagnetic phenomena.

The EMC standards should cover in principle four items :

• Emission requirements and tests
  • for low frequency disturbances
  • for high frequency disturbances
• Immunity requirements and tests
  • for low frequency disturbances
  • for high frequency disturbances (including ESD)

EMC harmonised standard will, of course, cover only the disturbances which are relevant to the specific products.