ASTM G 177 : 2003 : R2012

1.1The table provides a standard ultraviolet spectral irradiance distribution that maybe employed as a guide against which manufactured ultraviolet light sources may be judged when applied to indoor exposure testing. The table provides a reference for comparison with natural sunlight ultraviolet spectral data. The ultraviolet reference spectral irradiance is provided for the wavelength range from 280 to 400 nm. The wavelength region selected is comprised of the UV-A spectral region from 320 to 400 nm and the UV-B region from 280 to 320 nm.

1.2The table defines a single ultraviolet solar spectral irradiance distribution:

1.3The data contained in these tables were generated using the SMARTS2 Version 2.9.2 atmospheric transmission model developed by Gueymard (1,2).

1.4The climatic, atmospheric and geometric parameters selected reflect the conditions to provide a realistic maximum ultraviolet exposure under representative clear sky conditions.

1.5The availability of the SMARTS2 model (as an adjunct (ADJG173CD³) to this standard) used to generate the standard spectra allows users to evaluate spectral differences relative to the spectra specified here.