CLIMATIC & VIBRATION TESTING: ENVIRONMENTAL SIMULATION
❱❱ Simulation, left, takes products to likely extremes of service life; climatic test facilities can include drive-in chambers, such as this one at TÜV SÜD
Under stress to meet product quality
will perform its intended role in a mixture of environments throughout its design life. To get closer to achieving such
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confidence, designers and manufacturers must take a more active role in simulating the various environmental conditions to which the product will be exposed. This approach takes the product out of the comfort zone of the test bench and exposes it to the stress of real world conditions. TÜV SÜD Product Services at
Segensworth, Hampshire, says the link between product quality and environmental testing is obvious as it helps ensure it will not degrade and continues to fulfil its purpose when exposed to adverse conditions expected in normal use. Environmental testing can therefore help strengthen a brand’s competitive position in the market due to improved product performance and reliability by reducing the chances of failures in use.
SIMULATE OR REPLICATE? You can only simulate and not replicate an environment into which a product will be put. That is because there are so many variables, so while environmental testing can give confidence in a product’s reliability, extra unknown factors may come into play in the real world. For example, while you may have tested for a humid environment, you may not
here’s nothing static about product quality and reliability – a bench test and physical inspection simply aren’t enough to be confident that the product
TÜV SÜD explains to
Jonathan Newell the role of proactive environmental
simulation in meeting product performance specifications
STANDARDS
BS EN 60068-2 is a general standard which gives guidance on how to conduct environmental testing. Meanwhile, many industry sectors also have their own specific requirements which sit alongside this – such as RTCA/DO-160, which outlines environmental conditions and test procedures for civil avionics, and the USA military environmental testing standard, MIL-STD-810. However, as BS EN 60068 is not market or product specific, it is useful to tailor environmental tests specific to each individual product need. Such standards are not all-
encompassing and some designers make the mistake of thinking it is enough to ensure products comply with mandatory tests set out in product standards. But, for many products there are no specified environmental test requirements, and testing should therefore not be a ‘tick- box’ exercise. Using environmental testing to understand the impact of the unexpected during the product development stage will therefore future- proof developments, creating a robust and user-friendly product.
have anticipated that one particular user would leave the product in the sun for long periods of time, before rain rapidly cools it – humidity, solar and cooling effects are therefore difficult to accurately anticipate for each specific end-use situation. Environmental testing can therefore look
at a range of conditions including heat, cold, humidity, altitude, solar radiation, rain, condensation, atmospheric salt, shock & vibration and sand & dust.
A PROACTIVE APPROACH There are two types of environmental testing: reactive and proactive. Proactive testing is ideal, as without the ability to gauge reliability throughout the design lifecycle there is no assurance that the final product will meet market expectations. Making changes further down the design
process, or in response to product failures once released onto the market, are more costly than proactively testing for environmental concerns early on. So, not only should designers take into account normal conditions, but foreseeable misuse and external environmental influences also. Reactive testing is usually in response to
the failure of a product once it is on the market, which is not ideal. This can be quite common as the number of variables makes it impossible to cover all possible environmental situations. EE
❱❱ To read more on environmental testing online, scan the QR code or visit
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March 2018 /// Environmental Engineering /// 35
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