Electrical appliances have electromagnetic fields that are a result of electromagnetic emissions from them. Electromagnetic compatibility (EMC) can be defined as the unwanted production, distribution, and reception of electromagnetic emissions that cause damage to individual electronic appliances and also those that are close to them. The radiations from these appliances not only cause damage to them but also result in shocks and fire breakouts.
EMC testing on all electrical appliances is carried out for two reasons:
This is done to ensure that electrical appliances only emit the allowed amounts of radiations that would not affect their immediate environments. The appliances emitting waves that exceed those defined by the regulations, therefore, are unfit to be used in any environment.
This part of testing ensures that an appliance is safe enough to function properly even with the presence of the allowed amounts of radiations in their surrounding. Radiations cannot be completely eradicated but can be regulated to certain amounts that are safe for the environment. Appliances, therefore, should be immune to these allowed levels of radiations without their performance being impacted.
The Origin of EMC Testing
EMC testing has evolved with the evolution of technology. This has seen the transformation of EMC testing from analog methods to more digital ones. This is because of the evolution of appliances that could not accommodate the ancient methods of testing.
EMC testing was first realised in the 1800s when it was observed that when lightning ( electrostatic radiations that are experienced during thunderstorms) strikes a building then there are radiations that are emitted. The evolution of electrical appliances came with a lot of problems which included an increased number of electrical shocks. This problem became so common that it led to the invention and implementation of circuit breakers.
In the late 1880s, it was observed that electrical cables would produce sparks causing interference with each other and also interfering with telephone and telegraph lines thus impairing communication. This was a problem that had to be solved.
The 1900s saw the increased use of vehicles affecting radio waves and this served as a warning for the nations that had already developed. The beginning of the 20th century saw the evolution of the automobile industry with more cars and bikes. These automobiles produced radiations that affected radio and television signals. This time, not only sound was affected but also motion pictures that were shared in the televisions.
This shortcoming led to several developed nations passing the electromagnetic regulatory laws that would define the amount of radiation that is allowed from the automobiles. They required EMC testing of the automobiles. The electrical sparks that were observed from the power cables were now experienced with microwaves and ovens together with radio frequency emissions since these appliances also use radio waves.
There was also radiations from fast switching devices that affected the low voltages that were being used by devices. The electromagnetic regulatory laws that were passed because of automobile revolution now did not apply to these new devices.
The late 1900s saw the increase of mobile and broadcast devices that the increase the pressure that was already existing. The good thing about these devices was that they used digital signals that were not easily affected by electromagnetic radiations because their part was more optimized with software rather than hardware.
To date, electromagnetic regulatory laws keep changing to keep up with the ever-changing technology.
Examples of EMC testing equipment include: ERS (Emmission Reference Source), near field probes, amplifiers, chambers, test cells and analyzers.
Benefits of EMC Testing
In the present day today, there are so many manufacturers of different electrical appliances that are used in different environments. These appliances are either used independent of or dependent on each other. Either way, they all serve their different important purposes in society. EMC testing is important in ensuring that these appliances from different manufacturers either work together or coexist in the same environment.
It has been noted that string radiations from appliances damage individual and neighboring appliances and also cause shocks. These shocks are a threat to human life. EMC testing ensures that all these appliances are safe to use and also to work in common environments without causing problems for each other.
This benefit is realised when EMC testing is included in the development of these electrical appliances rather than at the tail end before deployment. Testing helps in building better designs that produce appliances that are pre-compliant to the EM regulatory laws. This is important instead of creating an appliance that completely fits the market needs only to have to retain it because of breaking the EM regulatory laws.
EMC testing without a doubt increase the costs of appliance production but for a worthy cause.