Description and classification of electromagnetic environments - revision of IEC 61000-2-5

Knowledge of electromagnetic environment where equipment is intended to be operated is an essential precondition for achievement of electromagnetic compatibility. The necessity of such a knowledge results from the fact that suitable immunity requirements can be concluded from corresponding data of the electromagnetic environment. Description of a general electromagnetic environment should consider a multitude of phenomena with a broad spectrum of parameters. Such a general description, however, is not helpful in most cases because it would imply that immunity against all such phenomena has to be taken into consideration. A more practical approach consists in introducing a classification scheme which gives a correlation between locations and electromagnetic phenomena there. This approach forms the basis of the document IEC 61000-2-5. Because of continuous change of existing technologies or introduction of new ones, electromagnetic environments in a certain respect change fundamentally. This is obvious in case of all the recently introduced radio and communication services with the generation of electromagnetic fields in the frequency range above 1 GHz. Hence it is needed to continuously monitor the electromagnetic environment and to adapt its description. Such an adaptation is done currently by a working group of IEC TC 77. The results of its work should be object of the next edition of IEC 61000-2-5. The present status as well as expected changes will be discussed in this paper.