Static natural weathering at Atlas in South Florida
Natural Weathering Testing
Accelerated laboratory weathering should always be complemented with outdoor exposure for
• correlating laboratory data with real-world ageing,
• determining acceleration factors,
• generating data for prediction models.
Outdoor weathering testing may be performed with direct solar radiation or sunlight behind glass, on static racks, tracking devices, or using sun-concentrating technologies (e.g. EMMAQUA).
Systematics of outdoor weathering testing
The majority of outdoor tests are exposures with backed or unbacked samples on static racks. The ASTM standard G113 on terminology calls this kind of outdoor exposure “natural weathering”.
Static Outdoor Weathering Exposure
The first systematic static outdoor weathering test was performed in 1906 using vertical East-West facing racks for exposing samples on both sides. Modern racks are usually inclined and South-facing on the Northern hemisphere to maximize solar radiation.
Atlas operates a worldwide network of outdoor exposure facilities in many geographic regions. Methods, processes, and technology meet all relevant standards. Certifications and accreditations cover a wide portfolio of testing needs. In addition to certified weathering testing services, many companies are interested in running their own outdoor weathering site with quick and easy access at their preferred location.
For this purpose, Atlas offers standardized Exposure Racks and Weather Stations.
Atlas Weather Station
Elinor Coatings Use Atlas Exposure Racks
Coatings designed for military assets pass rigorous laboratory testing followed by 12-18 months of outdoor weathering before products can pass the required specifications. Elinor Coatings is using Atlas Exposure Racks for their outdoor testing at McDill Airforce Base on the west coast of Florida. Their racks can hold up to 160 sample panels and host a solar-powered remote weather data station.
Elinor Coatings use Atlas Exposure Racks
Considerations for Your Own Outdoor Testing Site
If you intend to build your own outdoor weathering facility, here are key points to consider:
• Use state-of-the-art exposure racks, e.g. the Atlas Exposure Rack.
• Install a Weather Station to monitor key weather parameters.
• Meet international standards for outdoor exposure, e.g.
• ISO 877 Part 1 and 2 for plastics
• ISO 2810 for coatings
• ASTM G7 and G24 for nonmetallic materials.
More Information
To learn more, listen to a recorded online seminar on outdoor exposure testing, download a white paper on durability testing of coatings or review technical details of the Atlas Exposure Rack or Weather Station.
For further information on laboratory or outdoor weathering testing, check out our online library, educational calendar, or recorded online seminars.