Shielding Effectiveness of RFI/EMI Fingerstock Minimizing the Effects of Openings

The shielding effectiveness of an enclosure is a function of the involved frequency wavelength versus the longest dimension of the opening. A common example is the seam gap between door and sash of an electronic cabinet.

Shielding Effectiveness vs. Frequency

As a function of aperture length

Based on the above information, shielding effectiveness is determined more by openings rather than the shield materials. The opening around the perimeter of larger components, such as doors, vents, access panels and viewing apertures, present the greatest effect on the shielding and are the most difficult to seal. There are basically two ways to electrically connect the mating surfaces; first, by reducing the slot length through the use of conductive fasteners or welding at close intervals, second, through the use of RF gaskets to seal the opening. For additional information, please contact our Customer Service Department.