Power frequency magnetic fields and computer VDU interference phenomena

The interference by ambient 50 Hz magnetic fields on computer monitors or VDUs is an issue which has become prominent in recent times due to the widespread use of personal computers. Various options exist to resolve the interference problem by dealing either with the VDU or with the magnetic field sources including the selection of suitable locations or types of monitor, shielding or modification of equipment. For new installations, appropriate design and installation practices adopted at the outset can reduce or eliminate subsequent costly modifications.