Today, information technology consists of electronic components to a large extent. Optical
transmission technology is also increasingly used, but computers, network switching elements
and storage systems, for instance, usually contain a very large number of electronic
components. The function of electronic devices can be impaired or even damaged by
electromagnetic interference radiation acting on such components. As a consequence, this
may result in failures, malfunctions, incorrect processing results or communication errors
amongst other things.
Wireless communication can also be impaired by electromagnetic interference. Under certain
circumstances, a sufficiently strong interference of the frequency bands used is enough to
cause electromagnetic interference.
In addition, information that is stored on certain types of storage media may be deleted or
corrupted by electromagnetic interference. This applies particularly to magnetisable storage
media (hard disks, magnetic tapes etc.) and semiconductors. These storage media may even be
damaged by electromagnetic interference.
There are many different sources of electromagnetic fields or radiation, for example wireless
networks such as WLAN, Bluetooth, GSM, UMTS etc., permanent magnets and cosmic
radiation. Moreover, each electrical device emits more or less strong electromagnetic waves
which can be spread through the air, amongst other things, and along metallic conductors (e.g.
cables, air conditioning ducts, heating pipes etc.).
In Germany, the Electromagnetic Compatibility Act (EMVG) contains rules with respect to this
topic.