EMC certified inspection items
EMC certification of electrical products EMC certification projects include electromagnetic emission (EMI) and electromagnetic immunity (EMS) two aspects: electromagnetic emission (EMI) test items are:
Electromagnetic emission (EMI) test items are:
① continuous interference voltage (150kHz ~ 30MHz);
Intermittent disturbance voltage (150 kHz, 500 kHz, 1.4 MHz and 30 MHz);
Interference power (30MHz ~ 300MHz)
④. Harmonic current (2 ~ 40 harmonics)
Electromagnetic immunity (EMS) test items are:
Electrostatic discharge immunity
② radiation electromagnetic field (80MHz ~ 1000MHz) immunity;
③. Fast transient / burst immunity;
(4) Surge (lightning) immunity;
⑤. Injection current (150kHz ~ 230MHz) immunity;
Electromagnetic Compatibility EMC Introduction
With the development of electrical and electronic technology, household appliances are becoming more and more popular and electronic, radio and television, post and telecommunications and computer networks are becoming more and more developed. The electromagnetic environment is becoming more and more complicated and deteriorating, which makes the electromagnetic compatibility of electrical and electronic products (EMC electromagnetic interference EMI Electromagnetic anti-EMS) problem has also been the governments and production enterprises increasingly attention. Electronic and electrical products EMC (EMC) is a very important quality indicators, it is not only related to the reliability of the product itself and the use of security, but also may affect the normal operation of other equipment and systems, related to Protection of electromagnetic environment.
The full name of EMC is Electro Magnetic Compatibility, which is defined as "the ability of a device and a system to function properly in its electromagnetic environment and that does not constitute unacceptable electromagnetic disturbance to anything in the environment" First, the equipment should be able to work in a certain electromagnetic environment, that is, the device should have a certain degree of electromagnetic immunity (EMS); Secondly, the device itself can not produce electromagnetic interference to other electronic products too large Influence, ie, electromagnetic disturbance (EMI).
The EC government regulations, from January 1, 1996, all electrical and electronic products must be certified by EMC, CE mark affixed to the EC market after the sale. The move has had a wide impact in the world, and governments have taken steps to enforce the mandatory RMC performance of electrical and electronic products. Internationally influential, such as the EU Directive 89/336 / EEC (ie the EMC Directive), the US Federal Code CFR 47 / FCC Rules and so on have made clear requirements for EMC certification.
EMC certification using the standard
1, GB 4343-1995 "Methods of measurement and allowable values for radio disturbance characteristics of electric and electric appliances, electric tools and similar electrical appliances for household and similar purposes" This standard was issued on August 25, 1995 and implemented as of December 1, 1996 The
2, GB4343.2-1999 "electromagnetic compatibility of household appliances, power tools and similar equipment, the second part of the degree of immunity" The standard was published on March 23, 1999, April 1, 2000 from the implementation.
3, GB 17625.1-1998 "Harmonic current limit for low voltage electrical and electronic equipment (equipment for each phase current £ 16A)" This standard was issued on December 14, 1998 and implemented as of December 1, 1999 The At present, the standard is encouraged to adopt, if the failure will not be the basis for the overall judgment of the certification.
EMC sampling and judgment rules
1 samples were randomly selected from 30 to 50 sampling matrices. Three samples were used for inspection. One sample was used for enterprise retention. The number of mothers was more than 50, and 50 samples were randomly selected as sampling mothers The
2, the enterprise from the test for the use of three samples of any sample to send a sample to the designated EMC laboratory for testing, test results than the implementation of the provisions of the standard limit imposed by strict 2dB to determine.
3, if the measurement results of a single sample to meet the requirements of the implementation of the standard than the strict requirements of strict 2dB, then determine the sample inspection qualified.
4, if the measurement results of a single sample does not meet the requirements of the implementation of the standard certification requirements, then determine the sample test failed.
5, if the measurement results of a single sample to meet the requirements of the implementation of the standard certification requirements, but does not meet the requirements of the implementation of the standard than the strict requirements of strict 2dB, the enterprise should be extracted from the other two samples sent to the inspection agencies to test , If the results of the two samples submitted to meet the requirements of the implementation of the standard certification requirements, then determine the sample inspection qualified, otherwise determine the sample test failed.