The directive on electromagnetic compatibility is certainly one of the most interesting among those in force and it is an element present everywhere and certainly one of the less known and applied, let’s try to understand why.
Electromagnetical waves are virtually everywhere, and in some cases represent pollution for the world in which we live in.
The electromagnetic waves are generated by countless equipment that work with electricity and it is fundamental the presence of alternating current. Then there are the electromagnetic waves that are formed by natural causes, the most important and vital is the light.
The production of electromagnetic waves begins with the advent of electricity and with the discovery that the passage of current in a thread generates a magnetic field and if the current is alternating the field is not stable, but variable, with many positive and negative consequences.
The positive consequences are for example the electric motor, the transmission by air and substantially the great part of the communications of the modern era. The negative effects are reflected in disorders to equipment because of the waves that interact with them in an uncontrolled way.
The directive on electromagnetic compatibility is precisely related to this aspect, saying the detailed rules and limits of operation of electrical equipment, so that they not disturbed and are not disturbed by the waves.
It is necessary that the normal electrical equipments emit a limited number of electromagnetic waves and that the same has to be immune, at least until a certain level, from the waves that are normally present everywhere.
Of course there are jobs in which it is necessary to protect the equipment. In particular for medical purposes, aeronautic, military or others in which it is necessary to prevent that equipment disturb for example a mobile phone near the computer.
If it is true that everything that works with electricity produces electromagnetic waves, we must not however think that they should be subject to controls. We known for example that the trouble of a light bulb is not appreciable and important but already that of a neon light has its importance.
The equipment of normal use are already produced with components that emit limited disturbs, while particular attention deserve products that work with the waves, for example phones, for which it is necessary to ensure that they do not enter operating in the fields of other classes of transceivers such as radio, television, police. For that reason the CE marking of these products is one of the most complex and it is always required the intervention of specialized laboratories and notified bodies.
