Alternating climate test (ACT)

Realistic climate stress testing for metal components

IFO GmbH has many years’ experience and expertise as an accredited laboratory service provider in the fields of surface technology and metalworking. We have sites in Germany, China and the United Arab Emirates. Our state-of-the-art climatic chamber enables us to carry out demanding climatic cycle tests in accordance with industry-standard OEM specifications. 

The ACT test (Alternating Climate Test) is a tried-and-tested method for realistically simulating alternating climatic loads and is used to accelerate the assessment of the ageing behaviour of materials and components. In numerous sectors of industry – particularly the automotive, construction, aerospace and electrical engineering industries – the climatic resilience of materials and surfaces plays a crucial role. 

A climatic cycling test enables the early detection of material changes and potential damage resulting from cyclic fluctuations in temperature and humidity. The combination of elevated temperature and humidity, together with optional freeze and dry phases, recreates conditions such as those encountered in real-world applications over a period of years – but within a much shorter timeframe. 

Applications and objectives of the climate change test

The aim of a climatic cyclic loading test is to assess, under realistic conditions, the long-term behaviour of components when subjected to alternating climatic stresses. Both the mechanical properties and visual changes – such as cracking, discolouration or delamination – are recorded.

Thanks to the targeted combination of wet-dry cycles and temperature fluctuations, a climatic cycling test enables accelerated ageing testing – without the need to use corrosive media, as is the case with a cyclic corrosion test (CCT test). It is therefore particularly suitable for the preliminary assessment of climatic resistance prior to market launch or for quality assurance of production components.

Typical areas of application include:

• painted, coated or galvanised surfaces
• Exterior cladding elements
• Fasteners and metallic
• Paint-coated
• Plastic components for the automotive sector

The test comprises a recurring (cyclical) progression of different temperature and humidity values in order to simulate realistic environmental conditions. The sample is tested for visual changes (change in colour and gloss), damage (cracking and blistering) or dimensional stability.

Testing in accordance with standards and OEM specifications

We carry out climate change tests in accordance with current OEM and manufacturer standards, including, amongst others:

In addition, we meet the requirements set out in overarching specifications such as:

Among other things, these standards define test profiles with specific temperature and humidity profiles, the number of cycles, and evaluation criteria – such as changes in gloss, colour or dimensional stability. Our test chamber allows for flexible configuration of the climatic change profiles, thereby ensuring that customer specifications and standard requirements are met precisely.

Technical implementation of the climate change test in our chamber

Our technical equipment meets, at most, the technical standards required for an accelerated environmental test:

• Temperature range: -70 °C to +180 °C
• Humidity range: up to 98 % relative humidity. 
• Cycle control for temperature, humidity and drying phases 
• Inspection of components up to 1.5 m in length 
• intelligent control system for maintaining tight tolerances 
• Analysis can be carried out immediately after the end of the cycle

The test cycles used can last several days or weeks – with several cycles per 24-hour period.

Benefits of taking an exam with IFO GmbH

• OEM-level testing – tailored precisely to the requirements of your target customers 
• accredited procedures – OEM approval has also been granted
• High flexibility – special profiles are also possible 
• Short turnaround times – thanks to efficient laboratory coordination detail
• detailed assessment – including photographic documentation and assessment against standards 
• Advice from technical experts – with in-depth knowledge of materials 

As a specialist laboratory service provider, we offer you not only testing services but also expertise. We can advise you on the selection of standards, testing strategies and suitable methods of analysis.

Possible analyses following the examination

Once the climatic stress test has been completed, we will evaluate your samples in accordance with the relevant specifications. Commonly carried out evaluations include:

• visual inspection for cracks, discolouration or delamination 
• Gloss measurement before and after the test (e.g. in accordance with DIN 67530) 
• Assessment in accordance with in-house standards and ISO standards 
• Documentation including before-and-after photographs and test reports 
• Functional testing of component groups 

The ACT test compared with the CCT test

Whilst the ACT test primarily simulates temperature and humidity stresses without the use of salt solution or corrosive media, the CCT test (Cyclic Corrosion Test) also involves aggressive environmental conditions such as salt spray, SO₂ or acid rain. 

The ACT test is therefore particularly suitable for: 

• Weathering simulation without corrosive agents 
• Testing for material fatigue caused by climatic changes 

By contrast, the CCT test is ideal for assessing the corrosion resistance of metallic components – and, depending on the objective, the two methods can also be combined.