Jonathan Newell visited TÜV SÜD Product Services to find out about how EMC testing is keeping pace in a changing landscape.
TÜV SÜD’s Senior Engineer, Andy Lawson, is the kind of young, modern engineer that manages to keep pace with an electrical technology landscape that has never been subject to the kind of rapid change that’s taking place today.
Military, automotive and consumer technology are at the forefront of such changes with more function being crammed into tighter spaces with increasing levels of integration with other components, circuits and full systems.
Ensuring that such innovations stay within electromagnetic compatibility (EMC) standards is part of the task carried out by Lawson and his team and the level of equipment they have at their disposal to conduct the increasingly complex testing that is growing.
One of two locations within the UK, the Segensworth facility contributes to TÜV SÜD’s overall portfolio of testing capabilities which includes screened chambers of various sizes and EMC laboratories where tests can be performed for radiated or conducted emissions and immunity as well as transient testing and lightning simulation.
As part of a holistic engineering test facility for assessing compliance to a vast array of product standards, the EMC testing department at Segensworth has access to resources across all engineering disciplines.
A changing environment
The EMC environment is undergoing significant change, with higher power levels and more risk of interference. To understand this environment, there are three factors to consider:
Emissions – The unwanted radiation given off by a product
Interference – The degradation of product function resulting from emitted radio frequencies
Coupling – the transmission path between where the emissions originate and the product which suffers from the interference.
For complex systems in the aviation, military or automotive industries, density of devices can be problematic, particularly when individual components of the system have not previously been tested in conjunction with one another. Power levels are also higher than they have ever been before and so the susceptibility to interference is greater.
TÜV SÜD Product Services is able to supply testing services as well as consultancy and training to help product engineers to prepare earlier within the design process for gaining the certification that they need.
Another aspect of the changing environment for which testing must be provided is the greater exposure to electromagnetic fields of the human body. Lawson explained that this is particularly important with the growth in wearable technology. “We can test absorption rates for different RF devices with new equipment that has fast set-up times,” he told us.
The Specific Absorption Rate (SAR) is an important measurement for ensuring that human tissue is not exposed to hazardous electromagnetic fields when using certain devices. Although EMF as it applies to mobile phones is well understood generally, there are other devices which emit and which need testing such as the latest wearable electronic communication systems, household appliances, industrial and hospital equipment as well as broadcast and communication systems.
Other EMC services
Predominantly used by the aerospace industry, the lightning test facility is able to provide assessments of critical subsystems and their ability to withstand lightning strikes.
An important part of TÜV SÜD’s capabilities is in-situ testing. Although the company has large chambers where whole vehicles can be tested, there are sometimes occasions when it is impossible for the test subject to be brought to the Segensworth facility. In these cases, the company’s engineers perform in-situ testing. This is something that TÜV SÜD Product Services has gained experience in through working extensively in the aerospace industry where in-situ testing arrangements are most often favoured.