What aspects do EMC EMC test items include?

Date：2022-11-28 15:31:00Views：959

EMC, in Chinese, refers to the ability of the equipment or system to meet the requirements in its electromagnetic environment and not cause unbearable electromagnetic interference to any equipment in its environment. EMC test, also known as electromagnetic compatibility (EMC), refers to the comprehensive evaluation of electromagnetic interference (EMI) and anti-interference capability (EMS) of electronic products, and is one of the most important indicators of product quality.

EMC test includes electromagnetic emission test and electromagnetic sensitivity test (EMS and EMI). Electromagnetic compatibility test refers to the test to assess the electromagnetic compatibility of systems and equipment by using electromagnetic interference detection equipment and electromagnetic interference generation equipment under laboratory or field environmental conditions. EMC test objects include information technology equipment and household appliances, electric tools and similar equipment, fire-fighting electronic products, electrical lighting and similar equipment, industrial equipment, scientific and medical RF equipment, marine electrical and electronic equipment, automotive electronic components and vehicles, low-voltage switch and control equipment, etc.

Conventional EMC test items include the following:

1. Radiated emission test (RE)

Test the radiation emission of electronic, electrical, electromechanical equipment and its components, including the radiation emission from all components, cables and wires, to identify whether the radiation meets the requirements of the standard and affects other equipment in the same environment during normal use.

2. Conducted emission test (CE)

To measure whether the interference signal transmitted by the equipment from the power port and signal port to the power grid or signal network exceeds the standard.

3. Electrostatic discharge immunity test (ESD)

Test the anti electrostatic discharge interference capability of a single equipment or system, which simulates the discharge of operators or objects when they contact the equipment; Discharge of people or objects to nearby objects. Electrostatic discharge may cause the following consequences: damage to semiconductor devices directly through energy exchange, changes in electric field and magnetic field caused by discharge, and misoperation of equipment. The discharge noise current causes the malfunction of the device.

4. Immunity test of radio frequency radiated electromagnetic field (RS)

The interference to equipment is often caused by the operation of equipment and the use of mobile phones by safety inspectors. Radio frequency radiation interference will be generated by radio stations, television transmitting stations, mobile electric transmitters and various industrial electromagnetic radiation sources, as well as parasitic radiation generated by electric welding machines, thyristor rectifiers and fluorescent lamps. The purpose of the test is to establish a common standard to evaluate the resistance of electronic equipment to radio frequency radiated electromagnetic interference.

5. Electrical fast transient/burst immunity test (EFT)

The switching of mechanical switch to inductive load in a circuit will usually cause interference to other electrical and electronic equipment in the same circuit. The mechanism of the test is that the common mode current generated by the group pulse flows through the line and has the accumulation effect on the distributed capacitance energy of the line. When the energy accumulates to a certain extent, it may cause the line (and even the equipment) to work incorrectly. In general, once the test equipment makes mistakes, it will make continuous mistakes. Even if the pulse voltage is slightly reduced, the phenomenon that the errors are still continuous will be explained. Pulses appear in groups, pulse repetition frequency is high, waveform rise time is short, and energy is small. Generally, it will not cause equipment failure, and misoperation of equipment is common.

6. Lightning surge impact immunity test (Surge)

Surge immunity test (abbreviated as Surge), also known as lightning stroke test, refers to the energy generated by short circuit and arc fault of equipment combination to ground system and external lightning coupling, or directly striking external (outdoor) circuits, and injected large current flowing through grounding resistance or external circuit impedance, The surge (impact) immunity test mainly simulates the interference of the above energy on electronic products through connecting cables (power lines, etc.).

7. Conducted Immunity Test Induced by RF Field (CS)

Radio frequency interference caused by simulating radio frequency signals such as walkie talkies, mobile phones, base stations and coupling them to the EUT. It is mainly to evaluate the conducted immunity requirements for electronic equipment to withstand electromagnetic interference from RF transmitter within the frequency range of 150KHz~80MHz. The interference generated by coupling at least one connecting cable with the RF field will become conductive interference and invade the interior of the equipment, eventually affecting the equipment operation with the near-field electromagnetic field formed by the RF voltage and current.

8. Voltage drop, interruption during interruption and voltage gradual change immunity test

Voltage sags and short interruptions are caused by the faults of power grid and power facilities or sudden large changes in grid load. In some cases, there will be two or more dips and interruptions. The voltage change is caused by the continuous change of power grid load.

EMC test of electromagnetic compatibility also includes: power frequency magnetic field, pulse magnetic field, damped oscillating magnetic field, ringing wave, oscillating wave, low-frequency common mode conducted immunity, power frequency change, power port harmonic immunity test and other test items, but these test items are not particularly common, and power frequency magnetic field, pulse magnetic field, damped oscillating magnetic field, ringing wave and other immunity tests are required for general electrical equipment, wind power generation equipment, etc.

The above is the EMC EMC test related content compiled by the wound core detection team. I hope it will be helpful to you. Chuangxin Testing is a professional testing agency for electronic components. At present, it mainly provides integrated circuit testing services such as capacitance, resistance, connector, MCU, CPLD, FPGA, DSP, etc. Specializing in electronic component function testing, electronic component incoming appearance testing, electronic component dissection testing, acetone testing, electronic component X-ray scanning testing, ROHS component analysis testing. Welcome to call, we will serve you wholeheartedly!