Spectral Characteristics of Sunlight and Artificial Light Sources

2 SPECTRAL CHARACTERISTICS OF SUNLIGHT AND ARTIFICIAL LIGHT SOURCES 

The UVB spectral region is currently defined as encompassing wavelengths from 280 to 320 nm (Grossweiner, 1989). However, no solar radiation penetrates to the ground at wavelengths between 280 and 290 nm, and this remains true even in the case of a large reduction in atmospheric ozone such as occurs over Antarctica in 

Sunlight has a very high output in the visible (400 to 800 nm) and infrared (800 to 3200 nm) regions, while the incandescent lamp typifies black body radiation with a higher relative infrared output. The only importance that infrared radiation can accrue in the context of photodegradation is that the sample can be heated, thereby activating thermal decomposition. The visible region is relevant when a colored substance is present in the formulation. 

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