Electromagnetic Interference and Electromagnetic Compatibility in Rugged Computers
March 13, 2013
Electromagnetic Interference (EMI) is radiated electrical energy that disrupts the normal operation of electronic devices such as computers, cell phones, televisions; basically anything that has electrical circuits. Radio Frequency Interference (RFI) is the same as EMI, in general both terms can be used interchangeably.
EMI has two components, radiated and conducted electromagnetic interference. Radiated EMI are electrical fields that are generated by a device that creates interference in the operation of other electrical devices. Conducted EMI is how much radiated EMI is absorbed or received by an electrical device. All electrical devices are both EMI generators and receivers.
Radiated EMI from today’s advanced computers is a major concern and computer designer’s need to minimize the impact the computer has on other electrical devices located nearby. At the same time new computers are much more sensitive to interference from radiated EMI and design consideration must be given to protect the sensitive internal components from conducted EMI.
Most computer manufacturers design their products to minimize both radiated and conducted EMI to meet requirements for use by a consumer in an office or home. In the U.S. these standards are set by the Federal Communications Commission (FCC).
Computers and servers that are used in rugged industrial and military environments need to be designed to withstand much greater levels of EMI. Unlike a typical consumer environment an industrial or military computer may be placed next to a radar transmitter, power generator, or highly sensitive radio receiver.
To protect a computer from a EMI generator, such as a radar transmitter, the computer must be designed with special shielding and isolating electronics that far exceeds the shielding in a consumer product. Similarly a rugged computer must be designed so that EMI it generates (radiated EMI) are contained within the chassis and don’t interfere with highly sensitive devices, like a radio receiver.
Germane Systems designs their rugged computers and servers with unique shielding, special electronics and custom design techniques to insure that their computers will continue to operate error free even in the strongest EMI fields while not interfering with other sensitive equipment. The U.S. Department of Defense has created Military Standard (MIL-STD) 461 which is a series of test requirements that guarantee the computer will continue to operate in high energy EMI fields. Germane’s rugged servers and computers are tested by an independent test facility to verify that the rugged computers meet or exceed the standard.
When choosing a computer for use in environments where it will be exposed to high levels of EMI or where the computer may interfere with sensitive electronics it is important to choose a rugged computer that has been designed to generate the minimum of EMI and that can continue operate properly in strong EMI fields.
For more information about how German Systems can create rugged computer systems for your company that meet and exceed the requirements for EMC and EMI shielding, contact our office at (703) 502-8890.