Electromagnetic compatibility (EMC) Testing, approvals and certification

Electromagnetic compatibility EMC Testing

Why is EMC testing required?

EMC testing is usually legislated by law and mandated in many countries. Suppliers of products should have evidence of compliance. Regulators may request a supplier to show this documentation. Testing is not mandatory, but a technical rationale for not testing can be difficult. Generally, testing is the most straightforward and practical way to show compliance. You must conform to the EMC standards. The applicable standard may vary for the region of sale.

What is Electromagnetic compatibility testing?

‘Electromagnetic Compatibility testing’ abbreviated to ‘EMC testing’. It is the correct operation of a product when operating in the same electromagnetic environment as other products. Furthermore to avoid any interference effects thus allowing electromagnetic compatibility. You may have also heard the term EMI or Electromagnetic interference. It relates to EMC, read about what is the difference between EMC and EMI? Electromagnetic Compatibility compliance testing comprises two main parts. ‘Emissions’ and ‘Immunity or susceptibility’. Some countries mandate testing of only emissions. Countries such as Australia under the Regulatory Compliance Mark (RCM) scheme. And the United States, FCC testing. Also Canada, Innovation, Science and Economic Development (ISED). Other regions including the European community for the CE mark need both emissions and immunity EMC testing.

How do you get your product EMC tested?

EMC testing is usually part of the product compliance required. Consider the markets or compliance regions that you wish to distribute your product. Ensure that you have the technical information for the product. Contact an EMC testing laboratory and determine the EMC testing standards. Get an EMC testing quote, verify the scope of the compliance testing. Undertake the EMC testing and ensure that all other required product compliance is arranged.

How much does EMC testing cost?

Costs can vary considerably, depending upon the product and also the compliance requirements of the country. If the product is complex and has many cables etc, it may be more expensive. Whilst a simple battery powered product with a single mode of operation may be cheap. Your product may also need other product regulatory compliance. These may include wireless radio testing. This also falls under the scope of EMC compliance testing. It also may include EMC testing for medical devices for regions such as the USA, under the FDA guidelines.

Why use EMC Bayswater for your EMC compliance testing?

EMC Bayswater is a product compliance specialist, specialising in EMI and EMC testing. We provide accredited EMC compliance testing at our Melbourne EMC testing facilities. We use modern EMC testing equipment and software. Our staff regularly attend training seminars and have years of experience. Ready to assist in any electromagnetic compatibility engineering to achieve regulatory compliance.

Introduction to electromagnetic compatibility testing

EMC Testing of Emissions

EMC emissions testing can include various techniques. Used to measure different forms of energy and the means of which they propagate. Some of these tests include the following:

Radiated emissions and radiated disturbances

The measurement of radiated electromagnetic energy from an electronic device or apparatus. Either measuring the magnetic field (H field) or the electric field (E field) components. Depending upon the frequency range and also the EMC standard limits. Any electronic product may generate electromagnetic fields. These can propagate unwanted radio frequencies through the enclosure. This can be either ‘cabinet radiation’ or via connecting cables. Cables act as antennas ‘cable radiation’. Electric fields (E fields) are usually measured in V/m (Volts per meter). The units are usually scaled to make quantities easy to work with resulting in the unit dBuV/m. Magnetic fields (H fields) are scaled but the units expressed in A/m and used units are dBuA/m.

Conducted emissions and conducted disturbances

The measurement of conductive electromagnetic energy from product to the supply or terminal. This may include the AC, DC, signal or Telecommunication terminals. Measured using either a LISN, T-LISN, current or voltage clamp or network. The method of measurement depends upon the frequency range and the EMC standard. Any electronic product may generate electromagnetic fields that propagate unwanted radio frequencies. This may be via a conductive path. This could couple onto a wider network and cause interference. Conducted emissions are usually measured in V (Volts). And are usually scaled to make it easier to work with resulting in the unit dBuV.

AC mains port harmonic currents

Only usually needed for AC mains powered products for Europe (CE). The measurement of the harmonic content of the mains supply. The fundamental (50Hz) and the associated harmonics. This is to verify what harmonics will be on the local mains network with the product.

AC mains flicker

Only usually needed for AC mains powered products for Europe (CE). The measurement of the AC mains load variation test. This variation on the mains load on the supply network may affect other products. Typical products producing large switching loads would include washing machines, electric cooking products.

Immunity and susceptibility EMC Testing

Immunity testing is real-world phenomenon simulated using defined EMC testing techniques. Undertaken to ensure correct operation of a product within a specified tolerance. Test levels and ranges are dependent upon different standards. In addition to the products intended electromagnetic environment. Performance criteria are what would be acceptable to the end user or consumer or standard.

Radiated immunity or susceptibility

Radiated RF immunity to electric or Magnetic fields is the simulation of coupled RF on a product. This can be through either direct or cables. The product should withstand the effect. And the correct behaviour of the product maintained during testing.

Conducted RF immunity or susceptibility

Conducted RF immunity is the simulation cable coupled RF on a product. and the effect in the correct behaviour of the product. The product should withstand the effect. And the correct behaviour of the product maintained during testing.

Surges immunity

Surge immunity is the simulation of cable coupled surge transients. Via the AC, DC, functional earth or signal ports on a product and the effect in the correct behaviour of the product.

Electrical fast transient (EFT)

Electrical fast transients (EFT) is the simulation of cable coupled Electrical fast transients. This can be either the AC, DC, functional earth or signal ports.

AC mains voltage dips and voltage interrupts

AC mains voltage dips and interrupts is the simulation of abnormal mains supply. These can be a simulation of a blackout i.e. an interrupt. Or a brownout situation i..e a dip. Only applicable to the AC input ports. The type of voltage dips or interrupts is standard dependant.

Electrostatic Discharge (ESD)

Electrostatic discharge or ESD is the simulation of electrostatic discharges. These can include direct air, direct contact or indirect contact discharges. Simulating an electrostatic source such as a person to a product.

Vehicular transients

Vehicular transients are the application and simulation of various transient pulses. These pulses occur during normal operation of a motor vehicle. These transients can be coupled onto the cables such as power cables or wiring harness. Testing can include:

  • Supply disconnection of inductive loads
  • DC motors acting as generators after the ignition switching off
  • Cranking the engine
Share This