Are you looking for a simple breakdown of the meaning of EMC and its importance? You have come to the right place!
This will be a brief guide to understanding the basics of electromagnetic compatibility (EMC) and electromagnetic interference (EMI) in sensitive electronics and systems. We will look at how electromagnetic energy can interfere with medical and aviation systems as an example.
Moreover, you will learn which common household items can cause electromagnetic interference, why this can be an issue, and how this interference can be prevented, using EMC shielding. By the end of this guide, you will understand at a basic level what EMC is and why it is important. Let’s get started.
What Is EMC?
EMC stands for electromagnetic compatibility. This means that a device is compatible with its electromagnetic environment, no interference is caused, and it does not emit levels of electromagnetic energy that cause interference to other devices in the vicinity.
So, what is electromagnetic compatibility (EMC) testing, and why is it important? Basically, EMC testing measures the ability of equipment or systems to function satisfactorily and safely in their electromagnetic environment. This means they work without introducing disturbance to anything in that environment that could cause breakdown or dysfunction of other devices.
Electromagnetic Interference
Electromagnetic interference (also known as EMI) is unwanted noise or interference in an electrical path or circuit caused by an outside source. EMI is unwanted interference as it can cause electronics to operate poorly, malfunction, or stop working completely. This electromagnetic interference can be caused by natural or human-made sources.
There are different kinds of electromagnetic interference, such as continuous EMI, which is often caused by a circuit emitting continuous noise, and impulse noise, which can be caused by lightning, for instance. You can also have narrowband and broadband EMI. The former can be caused by a mobile phone or Wi-Fi router, while the latter can be caused by the sun. For instance, when the sun appears behind a satellite, it can cause a “sun-out” and briefly interrupt the signal to a television set.
Sources of EMI
Natural sources of EMI include rain spray, solar magnetic storms, electrical storms with high voltage lightning, and cosmic noises.
Inside the home, there are several kinds of man-made devices that can cause electromagnetic interference. These include various types of transmitters, doorbell transformers, toaster ovens, electric blankets, ultrasonic pest control devices, electric bug zappers, heating pads, touch-controlled lamps, and cellular phones.
As you can see, EMI can occur in many different surroundings due to the presence of common household and everyday items. However, there are some areas of life where this becomes a large problem.
Have you noticed that in hospital waiting rooms, it sometimes says on a sign on the wall that you are not permitted to use your phone beyond that point? This is because it is very important that medical equipment not be disrupted by the operation of other electronics, such as cell phones.
EMI and EMC In The Medical Field
There are standards for how electronics are designed that will determine whether or not they can be used in medical applications. Specifically, there are standards for electromagnetic interference (EMI) that have to be tested in order to meet the electromagnetic compatibility (EMC) requirements of medical devices.
There are many medical devices with potential sensitivity to electromagnetic fields, which can cause concerns for a patient’s health and well-being. These include pacing devices like defibrillators (ICDs) and pacemakers (ICPs), some neurological stimulators and shunts, hydrocephalus shunt valves, vagus nerve stimulators (VNS), drug infusion pumps, cochlear Implants, and reed switches.
Electromagnetic Interference And Commercial Flights
Another example of EMI prevention that you will be aware of but might never have realized is when you put your phone or tablet on flight mode on a commercial flight.
Electromagnetic interference from passenger-carried portable electronic devices (PED) has been reported on commercial airplanes. Phones and tablets are suspected of being responsible for anomalous events in flight due to their electromagnetic energy. These devices can interfere with air traffic control, which uses a ham radio. This is also a form of communication used in the medical field.
The operation of such PEDs produces uncontrolled electromagnetic emissions that seem to interfere with the plane’s systems. Airplane systems are tested rigorously to electromagnetic standards to establish control of their electromagnetic characteristics and compatibility. However, phones and tablets are not subject to these same equipment qualifications and certification processes, making them potentially unsafe to fly with when flight mode is not activated.
EMC Shielding
So, what can be done to minimize electromagnetic interference in sensitive electronics? Electronics companies can invest in EMC shielding. Remember, EMC stands for electromagnetic compatibility, which means that a system has been designed to prevent EMI by use of shielding.
The main purpose of EMC Shielding is to prevent electromagnetic interference from impacting susceptible systems and electronics. This can be achieved by using a metallic screen to absorb the electromagnetic energy that is being transmitted through the air before it can reach the sensitive system or electronics.
In your home, you will find EMC shielding in your speakers, which have an inner metallic casing to protect them from electromagnetic energy emitted by the microwave or TV set. EMC shielding is important to protect systems from breakdown or dysfunction, and as you have seen, it can save lives in certain walks of life.
This has been a brief guide to understanding the term electromagnetic compatibility (EMC) and its importance in the world of technology. As you have seen, the prevention of electromagnetic interference (EMI) by using EMC shielding is vital in medical practice and in aviation, as interference can lead to system failure, which in turn can lead to injury and even death.
Hopefully, now you understand that EMC compatibility is an essential component of electronics and systems and that it is something to be aware of. If you require the services of a professional EMC tester, reach out to an expert for guidance and assessment. This is a job that could save lives, or at least save your equipment from failure.
