Atlas Material Testing Solutions Ametek Measurement & Calibration Technologies

Accelerated Weathering

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If you should have questions regarding Atlas services and products or would like to discuss how Atlas can help you meet your testing needs, feel free to contact us.

Reasons for Testing

  • Competitive comparison
  • Standards need to be fullfilled
  • R&D (Rank materials by durability, compare new materials to "controls" or identify likely failure mechanisms)
  • Determine correlation of artificial testing results to real world
  • To support warranty claims / Service life prediction

What is Weathering?

Weathering is the adverse response of a material or product to climate, often causing unwanted and premature product failures. 

Natural Weathering   

Direct weathering, also known as outdoor or natural weathering, is defined as an exposure to direct sunlight and other elements of weather. Outdoor exposure tests can be done anywhere, from your backyard or roof exposure to the accepted reference sites. Globally recognized reference sites are subtropical Miami Florida and arid Phoenix Arizona. In addition to some of the harshest climates on earth, these sites offer a continuous record of relevant weather data. 

Accelerated Natural Weathering

Natural weathering can be shortened by intensifying the weather conditions. For example, solar radiation and temperatures in Miami Florida and Phoenix Arizona are more extreme compared to the climate in other locations.
Additional acceleration can be achieved by sun tracking and/or the use of fresnel mirror systems. 

Accelerated Laboratory Weathering

Because there is a need for more rapid evaluations of the resistance of materials to weathering than can be obtained by outdoor exposure tests, devices with artificial light sources are generally used to accelerate degradation. Traditionally for weathering carbon arc lamps have been used. Nowadays, more effective filtered xenon arc lamps or metal halide lamps represent a much closer fit to natural sunlight. For fast UV screening fluorescent light is also an option. 

Correlation and Acceleration

The reason for accelerated testing is to reproduce weathering effects in an accelerated manner. However, the changes of a material or product in the artificial test have to be the same as those in real life. Accelerating a test by intensifying test parameters (like solar radiation, temperature and water) requires a careful approach to ensure good correlation. Increasing the irradiance above its natural level (high irradiance testing) can help to shorten test times considerably, if the principle of reciprocity applies. The principle of reciprocity states that a specific property change depends on the radiant exposure (the total light energy) and not on the irradiance (the light intensity).


Atlas Material Testing Technology LLC 
1500 Bishop Court
 Mount Prospect, Illinois 60056, USA 

Phone: +1-773-327-4520
Fax: +1-773-327-5787

More Information Online

Read more about Weathering on the Atlas Corporate Website.

5 reasons to work with Atlas

  • Atlas products and services apply to a variety of industries such as automotive, paints and coatings, food and beverage, plastics and polymers, paper and packaging, chemicals and pharmaceuticals, textiles, and solar
  • Atlas offers an array of products and services that provide you with the knowledge you need to make informed material performance decisions to support your warranty and service life claims
  • Atlas offers a wide range of solutions to help you strengthen your market position and win new markets
  • Atlas provides technical support and instrument solutions to the textile industry for appropriate quality tests meeting all international standards
  • Atlas is an ISO 9001 and ISO/IEC 17025 accredited and recognized leader in quality control and quality assurance testing