What are the EMC test contents?

Date：2022-04-15 17:07:00Views：843

When interconnected or close to each other, all electrical equipment or devices endanger each other, such as the influence between TV, GSM mobile phone, tape recorder and surrounding automatic washing machine or cable. The purpose of electromagnetic compatibility testability (EMC) is to control all such adverse reactions in an effective range. EMC measurement mainly includes test field and test instrument, which is one of the important indexes of product quality. EMC test is used to detect the electromagnetic radiation generated by human body, public network and other normal electronic products. The definition includes two meanings: "a device or system can work normally in its electromagnetic environment and does not pose intolerable electromagnetic disturbance to any substance in the environment". First, the device should be able to work normally in a certain electromagnetic environment, that is, the device must have a certain anti electromagnetic interference ability (EMS); The electromagnetic disturbance generated by the device itself will not have too much impact on other electronic products, that is, electromagnetic disturbance (EMI).

EMC certification method

The quality certification process of machinery and equipment has been optimized into a single process. The third party is not mandatory to participate, but the manufacturer can choose to submit its technical data to the authoritative certification for evaluation.

EMC assessment can be conducted in three ways:

a) Application of EMC harmony specification

b) EMC evaluation, in which no unified standard is applied, and the manufacturer chooses its own way.

c) Mixed assessment, fusion of the first two methods. For example, harmony specifications can be applied to include discharge conditions and detailed technical EMC assessments at the immunity level.

It must be noted that EMC evaluation is the sole obligation of the manufacturer; It is by no means an obligation of third parties, such as publicity organizations or EMC test laboratories.

Main classification of EMC test

EMC is composed of EMI and EMS, which is called emiemiemiemi. This noise will not play its due role in other systems, but it is not good for the machine itself; EMS means that the machine will not be affected by the surrounding electromagnetic environment when performing its due functions.

1. EMI (electro magnetic interference) - electromagnetic disturbance test, which aims to detect the impact of electromagnetic radiation generated by electronic products on human body, public network and other normal working electronic products.

What are the main contents of EMI test?

Radiatedemission - radiation disturbance test.

Conductedemission - Conducted disturbance test.

Harmonic - harmonic current disturbance test.

Flickr - voltage change and flicker test.

EMS (electro magnetic immunity) - electromagnetic immunity test, which aims to detect whether electronic products can work stably in electromagnetic environment without being affected.

ESD anti static interference test.

Radiated anti-interference test of rs-rf electromagnetic field

CS - Conducted disturbance immunity test induced by RF field

Dip - voltage sag, short interruption, voltage change immunity test.

Surge Surge immunity test.

EFT - Determination of immunity to fast transient burst.

Pfmf power frequency magnetic field immunity test.

Definition of spurious: when modulating the standard test signal, it refers to the discrete frequency (existing remote radiation) other than the radiation of the carrier frequency band and the sideband and adjacent channels caused by normal modulation and switching. According to its source, stray radiation can be divided into conduction and radiation.

Stray degree: refers to the level power of any discrete signal measured under the 50 ohm load at the antenna connection.

Radiated stray: the enclosure of the test equipment Stray disturbance caused by interconnection cables. It is best to conduct the test in the anechoic room or outdoors, preferably in the electric wave.

In conclusion, EMC is a very important quality index. It is not only related to the working reliability and use safety of the product itself, but also may affect the normal operation of other equipment and systems, involving the protection of electromagnetic environment. The EU government stipulates that since January 1996, all electrical and electronic products must be certified by EMC and affixed with CE mark before entering the EU market.