We are surrounded by electromagnetic fields in our everyday life, that are generated consciously (for example through television, mobile communications, GPS,...) or unconsciously (for example when it comes to energy transmission or handling devices with electron stream) or even caused naturally (for example via the earth's magnetic field). Through their electromagnetic wave they can cause voltage or interference in wirings.
Electromagnetic compatibility (EMC) thereby indicates a condition that technical devices do not interfere with each other through unintended electrical or electromagnetical effects.
If the electromagnetic radiation meet with human tissue, energy of the radiation is absorbed and converted into heat within the tissue. This process generates so called radiation damages that can, depending on the intensity of radiation, lead up to kind of an combustion.
A shielding effect can be achieved with textiles for EMC-application while non-conductive yarns and twisted yarns are made conductive via coating or spinning with additional conductive fibres (silver, μ-stainless-steel or copper). They build kind of an Faraday cage, which reflects radiation or deducts from the object.
The EMC protective effect is usually measured in the frequency domain of 300 MHz - 3 GHz (radio-, TV-, mobile-, wifi-, flight control radar- and microwaves) and the screen attenuation is measured in decibel dB (logarithmic scale). Screen attenuation of 30 dB decreases the outlet of power at 0,1% and achieves screen effectiveness of 99,9%. Screen attenuation of 50 dB already achieves screen effectiveness of 99,999%.