What is Electromagnetic Interference?
Electromagnetic radiation arises from the movement of electrical charges and is a force containing electromagnetic energy. As all electrical and electronic devices themselves are affected by these electromagnetic waves, people are also exposed to some degree of disturbance. For example, electromagnetic waves are known to cause headaches, dizziness, fatigue, weakness, eye burns, and nighttime insomnia. These are the discomfort felt in a short time. There are also damages to human cell structures, molecular and chemical bonds and immune system. The chronic state of these disorders may lead to genetic mutations and cancer diseases in the future.
Electromagnetic field effects vary depending on power and field density, frequency, distance to or near source, exposure time, and measurements and electrical properties of the electromagnetic wave emitting device. Although the consequences of long-term effects in humans have not been fully elucidated, the above-mentioned effects are highly probable.
In order to illustrate the seriousness of the situation, the results of several experimental studies are given below:
- In 1993, Belgian scientists found damage to the P53 gene (a protein that regulates the cell cycle and is important for suppressing cancer in the organism).
- In studies conducted at the University of Washington in 1995, it was found that brain lesions occurred in mice.
- According to the results of the research conducted by the European Drug Organization of the World Health Organization, lymphoma cancer was detected in mice.
- The rate of increase in brain tumor in France for the last year was determined as 31 percent.
The short-term effects of electromagnetic field exposure are:
- Narrowing of the field of view
- Feeling too much stress and fatigue
- Concentration and attention deficit
- Tinnitus
- Temporary disruption of hearing
- Increased headache and dizziness
The long-term effects of exposure to the electromagnetic field are:
- Damage to cell growth
- Having permanent hearing disorders
- Increase in abortion in women
- Decrease in sperm count in men
- Blood brain barrier injury
- Increased heart disease
- Impaired memory
- Increased lymphoma cancer
- Disruption of genetic structure
Electromagnetic waves, for example, deform large molecules in cells, causing cell membranes to stick together and make holes on them and destroy the DNA structure.
Electromagnetic interference (EMI) is the event of high frequency electrical signal overlapping on an electrical signal. Such unwanted high frequency electrical signals are an electromagnetic interference. These signals can be transmitted over cables or can be carried by air propagation and may interfere with various control circuits or other electronic circuits, which may adversely affect their operation.
Although the subject of electromagnetic interference has been known before, it has become more important especially after the second world war. Electromagnetic interference today examines the effects of electronic circuits and electrical systems on each other.
What is Electromagnetic Interference Tests?
First of all, in the electronic circuits which are used in military systems more frequently, the problem of electromagnetic interference has begun to be addressed more when there are more interference problems and the attacks that are deliberately directed against the military systems increase. But in the civilian field this problem has become increasingly annoying.
The simplest examples of electromagnetic interference are mobile phone ringing when working on a computer or playing music on a stereo. In the meantime, distortions and vibrations on the computer screen, or the sizzling of the stereo speakers is a result of electromagnetic interference.
In 1982, the reason why Britain took over a destroyer in the Falklands war was that the radio system of this destroyer used for communication did not work correctly due to the electromagnetic interference between the missile detection system. To prevent this interference, the anti-missile system was temporarily shut down, at which point the missile destroyer was sent from the opposite side.
In 1967, one of the missiles on an American aircraft carrier in North Vietnam was involuntarily triggered by electromagnetic interference, hitting another aircraft and causing fuel tanks to explode.
As it is understood from these examples, reliability and protection of electrical and electronic circuits are very important in all areas of life. In order to avoid unexpected results, sources of electromagnetic interference must be identified. In this respect, electromagnetic interference measurements and tests performed by test and inspection organizations are of great importance.
In order to ensure that the measurements and tests to be performed by accredited test institutions are error-free, reliable, accurate and of high quality, these organizations maintain their processes in accordance with the TS EN ISO / IEC 17025 standard (TS EN ISO / IEC 17025 General requirements standard for the adequacy of the test and calibration laboratories).
Electromagnetic interference (EMI) is an important factor affecting the operation of electrical and electronic devices. Therefore, it is a matter of concern to manufacturers, designers, importers, retailers and ultimately consumers. Today, with the development of communication systems and electronic technology, both types and numbers of electromagnetic interference sources have increased significantly. Therefore, it is difficult to detect effects in devices in the environment of electromagnetic interference. Nevertheless, larger and more complex systems are now being produced, lower levels of interaction are being used, non-metallic housings are used in devices, data security requirements are increasing, and designs and methods that do not conform to electromagnetic interference are abandoned. In the light of these developments, electromagnetic interference tests are a solution proving the reliability of the products.
Numerous tests on electromagnetic compatibility and interference are conducted at the level of electrical and electronic devices, as well as at the systems level. The criteria used in these tests are determined as EMI and EMC standards, and these standards contain the main conditions that determine the quality of electrical and electronic devices. There are two important factors in these standards: test limit values and test methods. In addition, the tests are carried out in two ways: emission values and susceptibility values.
In addition, all tests are performed in four different environments: screened room, semi-reflection room, full reflection room and open field test area.
