weathering

Weathering is the adverse response of a material or product to climate, often causing unwanted and premature product failures, such as discoloration, cracking and crazing, rust, peeling paint, ... For product development, it is vital to understand how to properly design and conduct tests to prevent deterioration and premature product failure.

Laboratory Weathering ("Artificial 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 the degradation. The most common sources include filtered long arc xenon, fluorescent, metal halide lamps and carbon arc.

Advantages:

manipulation and acceleration of weathering conditions
tests can run continuously (f.e. no interruption by day/night cycle,...)
reproducibility and repeatability
each weathering condition can be controlled independently

Natural Weathering

An exposure to direct sunlight and other elements of weather.

Natural Accelerated Weathering

Ironically, as product life is expected to increase, new materials are being processed to decrease cycle times. Therefore accelerated testing is driven by economics as well as competitive factors.