FAQs-GW Instek

Q1

What are the test paths for the radio frequency (RF) part of the EMC test?

The path refers to the signal transmission methods of the DUT. There are usually two parts, which are transmitted through the wire or through the air. Therefore, in terms of test paths, both EMI and EMS tests include both conducted and radiated test paths, as shown below. In the EMC regulations, corresponding test regulations are also developed for these four situations.

The main details of the tests are shown in the table below.

Conducted EMI test (Conducted Emission)	The power cable of the DUT is connected to the simulated power supply impedance network (LISN) and the radio noise level of the product to be tested is transmitted to the measurement receiver to obtain the noise level.
Radiated EMI (Radiated Emission)	Under normal use, the radio of the DUT is received over the air to an antenna of 3M or 10M away, and then it is transmitted to the measurement receiver to obtain the noise level.
Conducted EMS test (Conducted Susceptibility)	The noise test mixed in the power cable and the control cable is used to test the interference of the DUT after coupling the noise and the power source, such as using an impulse test.
Radiated EMS test (Radiated Susceptibility)	Simulate the interference of the DUT exposed to electromagnetic waves, and transmit the required RF power by the antenna. The common test range is 80MHz~1GHz, and 1V/m ~ 10V/m with AM 80% modulation signal.

Q2

What is the complete EMC test content?

Electromagnetic compatibility (EMC, ElectroMagnetic Compatibility) consists of two parts, electromagnetic interference (EMI) and electromagnetic susceptibility (EMS). They mainly define that electronic products in the working environment can not interfere with the normal operation of other electrical products, and does not emit interference that other products cannot resist.

EMI focuses on the interference emitted by the device outward, while EMS focuses on interference emitted from external electronic products that interferes with the product. There are usually the following tests.

Q3

The difference between EMC certification and LVD certification.

Both EMC and LVD are test items under CE certification.

EMC is primarily defined in the Electromagnetic Compatibility Directive. The main test is to test whether the product is likely to cause interference (electromagnetic interference, EMI) and the ability to resist interference (electromagnetic susceptibility, EMS) during RF signal analysis.

LVD (Low Voltage Directive) is a directive under CE certification that specifies the hazard prevention requirements of electrical equipment under direct action, such as overcurrent protection, overvoltage protection, contact protection, over temperature, radiation, mechanical and non-mechanical factors, etc. . The scope of application of the directive is to use electrical products with a voltage between 50V and 1000V and a voltage between 75V and 1500V (voltage refers to the input or output voltage of the electrical product, and does not include the voltage of the internal circuit of the product).

Q4

What is CE certification?

CE (Conformité Européenne) represents a product that can comply with the relevant directives of the European Commission such as safety, health, environmental protection and other related directives. It is a self-certification program. According to EU regulations, if the product is to be sold to the EU, the product must pass the CE certification and show a CE mark on the product.