Low Frequency Magnetic shielding

Magnetic shielding using special materials to provide shielding against low frequency magnetic field generally created by local power supply which are 50 and 60 hz. The measured magnetic field density increases with current, the type of source like power transformers or cables etc., the distance and angle of source .These low frequency magnetic fields are difficult to shield and we Frank shields specialize in providing a cost effective solution for the same,]magnet room or even the magnet itself. This concentrates magnetic flux lines, reducing the fringe field beyond the shielding.Passive shielding (see also Faraday cage) significantly eases the problems of siting a MR Image in a confined space. Ferromagnetic objects are less prone to being attracted to the magnet, ancillary electronic equipment,credit cards and computer disks can be brought closer to the magnet and the MRI safety limit for pacemaker wearers (the 5 gauss line = 0.5 mT) is reduced from, typically, 10 m to 2 m from the magnet. A passive shield for a whole-body MRI magnet weights many tons. An alternative method of controlling stray field is active shielding