What is electromagnetic field conducted interference testing

emc testing, also known as Electromagnetic Compatibility (EMC), refers to a comprehensive evaluation of electronic products concerning the amount of interference in the electromagnetic field (EMI) and their ability to resist interference (EMS). It is one of the most critical indicators of product quality. The measurement of electromagnetic compatibility consists of test sites and test instruments.

The purpose of EMC testing is to detect the impact of electromagnetic radiation generated by electrical products on humans, public power grids, and other electrical products operating normally.

Electromagnetic compatibility is a discipline that studies the coexistence of various electrical devices (broadly including organisms) in limited space, time, and spectrum resources without causing degradation. It includes two parts: electromagnetic interference and electromagnetic susceptibility. electromagnetic interference testing measures the strength of interference on surrounding electronic devices by detecting the size of the electromagnetic waves emitted by the tested equipment in normal working conditions. Electromagnetic susceptibility testing measures the ability of the tested equipment to resist electromagnetic interference.

Electromagnetic interference mainly includes radiated emissions and conducted emissions.

Radiated Emission:

Electromagnetic interference transmitted through space in the form of electromagnetic waves.

Conducted Emission:

Electromagnetic interference propagated along conductors.

Test Sites:

- Open-area test sites

- Semi-anechoic chambers

- Shielded rooms

Main Electromagnetic Interference testing Equipment:

1. Anechoic chamber

2. Receiver

3. Receiving antenna

4. Artificial power network

5. Power absorption clamp

6. Turntable and lift platform

7. Turntable and lift platform controller

Electromagnetic Compatibility Testing Items:

- Conducted emission (9kHz-30MHz)

- Power clamp emission (30MHz-300MHz)

- Magnetic emission (9kHz-30MHz)

- Radiated emission (30MHz-18GHz)

- Click conduction interference

- Harmonics (class A, B, C, D)

- Voltage flicker (flicker plt, pst)

- Electrostatic discharge (ESD ±0.1-±16.5kV)

- Radiated immunity (below 1GHz)

- Electrical fast transient/burst (EFT/B ±0.1-±4.4kV)

- Surge (0.1-6.6kV)

- Conducted susceptibility (CS 0.1-30V)

- Magnetic field immunity (MS 0-120A/m)

- Voltage dips (0%-100%)

- Oscillatory waves surge (0.1-6.6kV, 100kHz waveform)

- Harmonic and interharmonic immunity

- Magnetic field EFM 10Hz-400kHz (EN50366)