Computer and electronic systems complex structure and their sensitivity to external factors and then their increasing use in offices, industry and clinical environments, have brought their safety and performance under close scrutiny; thence, drive the manufacturers to upgrade the reliability factor of their products
The existing problems in applying such equipment are partly due to the interference of unwanted signals which disturb their function, or may harm or damage them. This phenomenon can cause heavy economic and industrial damages or even loss of lives.
Electromagnetic compatibility is a field in which the effect of working equipment in interaction with their environment is studied. These effects may be viewed from two different points: 1- Interferences emitted into the environment by the equipment (emissions) 2- The interferences from the environment to which the equipment are exposed (immunity).
Equipment is considered conforming to electromagnetic requirements providing that it meets the following conditions:
1-Its emissions into the environment causing disturbances do not reach the limits specified in the standard (emission tests).
2-Show enough immunity against certain level of disturbances (immunity tests).
Electromagnetic compatibility tests are performed in EMC laboratory according to the following standards, on products such as IT and electronic equipment, audio-visual units, medical devices, and so forth:
IEC/EN 61000-4-4 (Electrical Fast Transient/Burst Immunity Test)- Corresponding to National Standard 5237.
IEC/EN 61000-4-5 (Surge Immunity Test)- Corresponding to National Standard 7260-4-5
IEC/EN 61000-4-6 (Immunity to Conducted Disturbances, Inducted by Radio- Frequency Fields)
IEC/EN 61000-4-8 (Power Frequency Magnetic Field Immunity Test)- Corresponding to National Standard 5237.
IEC/EN 61000-4-11 (Voltage Dips, Short Interruptions and Voltage Variations Immunity Test) - Corresponding to National Standard 7260-4-11.
Emission Tests:
EN 55022/CISPR 22(Information Technology Equipment - Radio Disturbance Characteristics)
EN 55011/CISPR 11(Industrial, Scientific and Medical(ISM) Radio – Frequency Equipment - Radio Disturbance Characteristics)
EN 55013/CISPR 13(Limits and Methods of Measurement of Radio Disturbance Characteristics of Broadcast Receivers and Associated Equipment).
IEC/EN 61000-3-2 (Limits of harmonic current emissions for equipment input current up to and including 16 A per phase)- Corresponding to National Standard 7260-4-5
IEC/EN 61000-3-3 (Limitation of voltage fluctuations and flicker in low-voltage supply systems for equipment with rated current up to 16 A)
Standards for test of common products:
EN 55024/CISPR 24(Information Technology Equipment - Immunity Characteristics) - Corresponding to National Standard 7261.
IEC 60601-1-2 MEDICAL ELECTRICAL EQUIPMENT –Part 1: GENERAL REQUIREMENTS FOR SAFETY 2. COLLATERAL STANDARD: ELECTROMAGNETIC COMPATIBILITY - REQUIREMENTS AND TESTS
ETSI EN 301 489-1 Electromagnetic compatibility and Radio spectrum Matters (ERM); ElectroMagnetic Compatibility (EMC) standard for radio equipment and services; Part 1: Common technical requirements.
ETSI EN 300 386 Electromagnetic compatibility and Radio spectrum Matters (ERM); Telecommunication network equipment; ElectroMagnetic Compatibility (EMC) requirements.
