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What is EMC testing and why is it required? If you are looking to launch any sort of electronic device to market, you need to understand EMC testing. Please read below as we take a deeper look into this topic.

Worldwide regulatory bodies have placed limits on the levels of electromagnetic emissions that can be generated by electronic and electrical devices.

Electromagnetic Compatibility (EMC) testing is used to ensure that electronic or electrical products do not emit large amounts of electromagnetic interference and also to ensure that devices continue to function as intended when subjected to several electromagnetic phenomena.

EMC testing and certification can be a huge burden to small as well as large manufacturers and sometimes its effectiveness can be questionable.

However, EMC rules emerged as a result of real problems experienced in the field that prompted governments and private infrastructure to accommodate and enforce these rules with electromagnetic immunity testing being mandated in some areas and for some product types.

If you are in any way involved in the design, manufacture or import of products that contain electronics, you will most definitely need to determine whether emissions and immunity tests apply to your products and exactly which standards apply.

This testing must be performed by a recognised EMC testing body to ensure that full compliance is met for testing and certification purposes.

Why EMC Testing is Necessary

Electronic devices have the potential of being vulnerable to electromagnetic fields.

With excessive numbers of these devices in the hands of the global population, the capacity for various devices to interfere with each other becomes apparent.

This has prompted regulatory authorities to state that electronic and electrical products need compliance and that they cannot be recognised as complete until all aspects related to EMC testing have been considered.

This does not just apply to commonly used products such as electronic devices, televisions, computers, and household appliance among others.

It also incorporates sensitive and high-tech products particularly sensitive to EMC influences such as aircraft, vehicles, ships, and large industrial installations.

In some countries like Canada and the United States, only emission testing is currently required (unless products fall under the scope of industry-specific standards that require immunity testing as well).

However, in Europe, both emissions and immunity testing are mandated. Countries such as Australian and New Zealand have followed the European model over the past few years.

There has been a big push from internal governments, test labs, and international standards signifying an increase in requirements for immunity testing.

Why EMC Testing is Important for Everyone

• Protection of the Electromagnetic Spectrum

There is only a certain amount of electromagnetic spectrum available for use by things like x-ray machines, radio transmissions, and microwave transmissions as well as a number of other products.

Even without transmitters, electronic devices continually emit electromagnetic radiation simply as a byproduct of switching voltages and currents inherent in electronic circuitry.

If there are no limits to the amount of unintended electronic radiation emitted by these products, our electromagnetic spectrum can be adversely affected, compromising frequency bands reserved for things like radio transmissions.

The continued explosion of wireless and non-wireless electronic products on the market has resulted in the electromagnetic spectrum being more crowded than ever.

In order to ensure that electronic devices continue to function properly in the future, the protection of the electromagnetic spectrum is essential.

• Safety Concerns

EMC performance for many industries and products can mean the difference between life and death which is why many industrial, military, medical, automotive, and aerospace products have safety-critical applications.

• Product Quality and Performance

The performance and function of electronic products can be adversely affected by internal and externally generated EMC phenomena such as in internal power supply that is too noisy.

External EMC phenomena can affect devices in a number of ways including measurement accuracy, data corruption, RF performance, and IC frying.

EMC testing can not only help you meet regulatory requirements and reduce the risk of costly non-compliance but can also help improve product performance.

This, in turn, will help to strengthen your competitive position in the industry as it is regarded as a long-term investment by many manufacturers.

If you would like to know more about the EMC standards and product testing or need EMC testing done, then look no further than Compliance Engineering.

We are the definitive source for all of your Electromagnetic Compatibility (EMC) requirements. Please call us today on + 61 3 9763 3079 or contact us here.

Do you have an electronic device that is being manufactured? Did you know your product needs to be tested for electromagnetic compatibility? This article will explain what happens with this process.

All electronic devices and electric equipment make use of electromagnetic waves produced by electrically charged particles in motion. This electromagnetic radiation travels through the air, empty space, and other substances.

The full range of wavelengths and particles called photons forms the ‘electromagnetic spectrum’.

Regulatory compliances require that electronics undergo electromagnetic testing, a critical step when bringing a new product to the market.

What is EMC and EMI Testing?

Generally speaking, electromagnetic testing should only be performed by a recognised EMC testing body. The testing is grouped into two categories, emissions testing, and immunity testing.

– Emissions Testing

The purpose of emissions testing is to ensure that emissions from the device being tested are below the limits relevant for that type of device.

Basically it measures the amount of electromagnetic ‘noise’ generated during normal operation of the device.

The tests can provide reasonable assurance that the device will not emit harmful interference while operating within its normal operating environment.

– Immunity Testing

The purpose of immunity testing is to ensure that the device will operate as intended within its expected operating environment and how it reacts when exposed to disturbances such as electromagnetic noise from other devices or equipment.

Regulatory compliance requires both types of testing. The most common applications for electromagnetic testing are:

– Medical devices where devices must work together in close proximity without performance being compromised by interference or electromagnetic noise.

– Military or Aerospace devices to meet standards for avionics equipment and other goods.

– Consumer products such as cellular phones, satellite TV dishes, laptops, and microwave ovens to avoid harmful interference in real-world conditions.

What is the Difference Between EMC and EMI Testing?

Both types of testing are vital for electronic product development and companies across the world are required to comply with EMC/EMI limits finalised by standard bodies before launching products to the market for consumer use.

EMC (Electromagnetic Compatibility) and EMI (Electromagnetic Interference) testing are essential to verify the electromagnetic levels mentioned for any manufactured device.

Designers need to consider the specific military or industrial standards required for products under development.

How to Measure EMC and EMI Emissions

An electromagnetic field consists of two components:

– Electric Field or E-Field measured in V/M (volts per metre)
– Magnetic Field or H-field measured in A/m (amps per metre)

These two fields move at right angles to each other.

Emissions are subdivided into Radiated and Conducted Emissions

Radiated Emissions Testing

This test measures the electromagnetic field strength of emissions unintentionally generated by a product, how large they are, and if they comply with emissions limits set for the particular product.

Radiated emissions measurements are done by using a spectrum analyser and/or EMI receiver as well as a suitable measuring antenna.

The frequency band of interest will be scanned in a test lab to detect emissions that are close to the limits. A process called ‘maximisation’ is used to focus on these emissions and quantify the amplitude of their field strength.

Two primary test sites used for this purpose are:

– Open Area Test Sites (OATS)
– Semi Anechoic Chambers

Conducted Emissions Testing

As a device creates electromagnetic energy, a certain amount is conducted into the power supply cord. Test labs measure these emissions to verify that they comply with the specified limits.

A typical conducted emissions test involves one or more LISNs placed between the power source and an EUT (Equipment Under Test) that filter and isolate unwanted RF signals.

LISNs help to minimise external noise, allowing the lab to only measure noise from the EUT device.

Passing EMC/EMI testing will depend on several factors such as a good understanding of the process involved, the skill of the designers, and proper preparation. The estimated failure rate for first-time passes is 50%.

An EMC design review before designing a product or sending a device to an EMC test lab can help check your product against industry-standard best practices and issues that could increase the chances of first-time pass failure.

If you would like to know more about the EMC standards and product testing or need EMC testing done, then look no further than Compliance Engineering.

We are the definitive source for all of your Electromagnetic Compatibility (EMC) requirements. Please call us today on + 61 3 9763 3079 or contact us here.