What is ISO/TR 17801- global solar spectral irradiance at sea level about? 
The effect of solar radiation on the surface of the earth is the most important primary weathering factor. The photons absorbed by the molecules during radiation exposure are often sufficient to split chemical bonds, start photochemical reactions and cause an electron transfer.
ISO/TR 17801 provides a reference spectrum to the field of weathering degradation in order to classify solar simulators in the UV, visible and infrared wavelength range. The photochemical ageing which occurs in practice is simulated with time compression in laboratory weathering instruments by sequencing maximum stress climate episodes.
Who is ISO/TR 17801 - global solar spectral irradiance at sea level for? 
ISO/TR 17801 on global solar spectral irradiance at sea level is useful for:
- The plastics and polymer industry
- Manufacturers of plastic products
- Manufacturers of products that incorporate polymers such as awnings, roof tiles, decks etc.
- Product development and research teams
- Manufacturers of PVC and PVC-O products that are exposed to sunlight such as irrigation pipe systems
Why should you use ISO/TR 17801 - global solar spectral irradiance at sea level?
The spectral irradiance of the solar radiation is variable locally and in time. A reference spectrum is therefore required as a basis for the simulation of the spectral irradiance of solar radiation with artificial radiation sources/radiation systems.
To give a spectral irradiance target, ISO/TR 17801 specifies the spectral irradiance of global radiation with a cloudless sky, zenith position of the sun by day and night comparisons at the equator at sea level. This is a realistic maximum exposure under representative clear sky conditions. ISO/TR 17801 provides modelled data generated using an air mass zero (AM0) spectrum based on the extraterrestrial spectrum of Gueymard.
The guidelines in ISO/TR 17801 help you classify solar simulators in the UV, visible and infrared wavelength range for industrial applications so that the end customer gets a superior quality product.
