Go to GlobalSpec.com Home
Newsletter   FREE GlobalSpec e-Newsletters
Receive the latest news, trends, and technology relevant to your work.
(See Titles)

EMI Shielding With Perforated Metals

From Diamond Manufacturing Co.
 

 

One of the most common uses for perforated metal is to enclose electrical devices to attenuate the EMI/RFI radiation they emit and to ventilate them at the same time. Many questions have been asked about which perforated pattern should be used to satisfy both of these design requirements and the shielding effectiveness of various perforated patterns and materials. To answer these questions, the Industrial Perforators Association contracted Intertek Testing Services, testing laboratories in Boxborough, MA to evaluate the shielding effectiveness of 16 perforation and material combinations at 13 frequency levels. The results of these tests with descriptions of the test samples and the frequencies tested are shown in the charts, CLICK HERE TO VIEW CHARTS. Results have been expressed in dB of Shielding Attenuation and in % of Attenuation.

The test results show that a Shielding Effectiveness of 40 dB provides 99.000% attenuation of the electromagnetic (EMI/RFI) radiation while a Shielding Effectiveness of 92 dB, the highest Shielding Effectiveness found in the tests, provides 99.997% attenuation. A Shielding Effectiveness of 40dB is the targeted minimum in most applications.

Product Announcements
Diamond Manufacturing Co. - EMI Shieding Effectiveness for Perf Metal
One of the most common uses for perforated metal is to enclose electrical devices to attenuate the EMI/RFI radiation they emit and to ventilate them at the same time. (read more)
Select Fabricators, Inc. - EMI Shielding Curtains for Testing Capabilities
Select Fabricators, Inc. specializes in EMI flexible shielding utilizing the best quality materials and processes available in the industry. (read more)
Dontech Incorporated - EMI/RFI shielding
Custom Optical Filters Dontech engineers and manufactures a broad range of custom display filters for: EMI/RFI shielding via optical fine wire mesh and conductive coatings... (read more)
Compac Development Corporation - Precision RF Shielding for less money
Compac's unique product line can easily be tailored to meet your many specifications. But if our RFT, Blank or SRF Series do not fit your basic requirements, Compac can build a totally custom... (read more)
Equipto Electronics Corporation - High attenuation EMI/RFI Enclosures
EMI/RFI shielded electronic enclosures from Equipto Electronics provide an exceptionally high 80 db of attenuation from 200 MHz to 1 GHz and 60 db from 1 GHz to 10 GHz. Cabinets also meet requirements... (read more)
 
Topics of Interest
Duct Tape and Test-Time Bandages Despite thorough engineering, surprises do happen during compliance testing. Inevitably, while you are still giving the last touches to your design, the marketing... (Read More)
The Department of Materials Science and Engineering at Ohio State University using methods, tooling, and a testing machine of their design, generally referred to as the OSU Formability Test, were... (Read More)
Conductive coatings consist of a metallized layer deposited through thin film (evaporation or sputtering), plating, or thermal spray processes. They are applied to enclosures that house electronic... (Read More)
The charts below demonstrate the effectiveness of Ventiduct for heat control by thermal radiation. The Ventiduct reduces the temperature rise in the valve by approximately 12°C. Test Conditions: Fluid... (Read More)
GOOD DESIGN PRACTICES, REMEDIES, AND DUCT TAPE No cure for EMC problems is better than prevention. Trouble avoidance in EMC is accomplished by considering the emissions and susceptibility aspects of... (Read More)