What Is EMC Testing?

Electromagnetic Compatibility testing, also known as EMC testing, has become an important element to design engineers all over the world.

The European Union, as part of CE Marking, has a legal requirement that electrical products/equipment must not emit harmful levels of electrical noise above which radio and telecommunications equipment or other equipment cannot operate as intended. They must also have a level of immunity to electromagnetic disturbances which allows for proper operation.

What Type Of EMC Testing Is Conducted?

EMC testing includes two main types of testing:

  • Emissions Testing measures the amount of electrical noise generated in the form of radiated and conducted emissions.
  • Immunity Testing measures how a device reacts to natural electrical disturbances in a variety of forms. 

What Are The Types Of EMC Testing Being Conducted?

  • Conducted Emissions is electromagnetic energy that is coupled back onto the power cord which could affect nearby devices connected to the local power supply. 
  • Radiated Emissions is cavity electromagnetic fields that propagate away from the equipment under test over the air. Testing involves measuring the intentional and unintentional electromagnetic field released from the equipment under test. Emissions are generated by switching voltages/currents from any digital source.
  • Electrostatic Discharge involves a controlled ESD that is applied to any area of the product which is accessible to human touch. A Contact Discharge Tip is used to apply ESD to a conductive surface. An Air Discharge Tip is used to apply ESD to any non-conductive surface.  
  • Radiated Immunity is a calibrated RF signal which is broadcasted over the air into the equipment under test to simulate different types of electric field disturbances which the product could encounter from other products.
  • Electrical Fast Transients is a simulated switching of inductive disturbances which the equipment under test can experience from sources such as motors, relays, fluorescent ballasts, etc.
  • Surge is energy caused by overvoltage switching or nearby indirect lightning strikes. A typical product can experience a few power surges per year.
  • Conducted Immunity is a test used to determine an overall immunity to radiated fields. These fields are coupled directly into the equipment under test power cord using a coupling decoupling network or coupled onto the I/O lines using an EM clamp or a bulk current injection probe.
  • Voltage Dips & Interruptions is a test to help ensure equipment under test still functions as intended while subjected to power supply voltage fluctuations. Duration and depth of dip are defined by the standard under which the product is evaluated. Interruptions are caused by faults in the network or large sudden change in load.

Where Can EMC Testing Be Conducted?

Testing can be done at your facility (in-situ) or an accredited test laboratory. Testing at your facility has added benefits enabling you to set-up and monitor your equipment, and allowing us to easily assist your engineers should any testing issues arise.   

At Technology International, our EMC test engineers can work closely with your staff for troubleshooting and provide recommendations to help remedy test failures.