MAGNETIC SHIELDING Continued from page 2

The information obtained from conducting the site survey will dictate an appropriate shield design. With knowledge of the magnetic fields' locations, we can determine what materials are best to use, the required thickness and how many layer are needed Magnetic fields cannot be simply blocked, as with some higher non-magnetic frequencies, but can only be redirected away from the object or area you are attempting to shield

Magnetic shielding materials offer a very high permeability path for magnetic field lines. By directing the electromagnetic energy through the thickness of the alloy, the field is kept from going where it is not wanted. The shield must create a complete path for the field lines, so that they do not exit the material in a place where they will cause unintended interference.

Wall and room shields should not have uncovered seams. Installation requires that sheets must be overlapped or butted with foil shielding material applied over the butt seams. Once the shield is installed, an additional survey should be made to confirm the results. If necessary, adjustments can then be made to the shield application.

Unlike RF (Radio Frequency) shielded rooms, magnetic shielding does not usually require a full, six-sided enclosure with sealed doors in order to solve a problem in a room. Materials are typically applied on the surface (floor, wall or ceiling) between the interference source and the area requiring protection. Small openings have little effect on the shielding performance.

JOURNAL OF MAGNETIC SHIELD CASE STUDIES

Middle School Computer Lab.

A midwestern middle school had a new computer lab installed for its students. The architect recommended a very typical design that added the room next to the power distribution room. This design enabled reduced expensive rewiring often associated with school additions of this type. Unfortunately the power panels generated magnetic interference that distorted the monitor screens in the lab rendering them impossible to use. After conducting the site survey, shielding was applied on the walls between the power panels and the adjoining room.

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Magnetic Shield can provide a site survey at your facility. One of our experienced engineers will travel to your site, perform a complete survey and write a detailed report outlining the suggested steps to mitigate your EMI/EMF problem efficiently and effectively. MSC engineers combine the latest technological detection apparatus with years of experience. This "know how' translates the collected data into a personalized, workable mitigation plan for your specific application.

This service has become increasingly important as offices, manufacturing environments, public buildings, high-rise apartments and other locations are subject to higher levels of EMF interference. Contact Magnetic Shield Corporation to receive an estimate for a site survey at your facility.