There is a great need for photochemical and photobiological experiments to mimic the spectral distribution of solar ultraviolet radiation by artificial ultraviolet sources. The spectral distribution of various ultraviolet sources were compared with a reference solar spectrum which represents a realistic maximum solar spectrum under cloudless sky. Various methods to compare the artificial sources with the COLIPA solar reference spectrum were presented. Beside a graphical method which is based on the Lorenz curve also integral indices were used to characterize the deviations from the solar spectrum. Following parameters should be used to characterize an artificial source: (1) total output of the biologically effective irradiance, (2) maximum deviation of the cumulative relative spectral irradiance of the biologically effective solar simulated radiation, (3) spectral distribution of the difference of the cumulative relative spectral irradiance of the biologically effective solar simulated radiation, and (4) the index of the goodness of the spectral fit. Further on upper and lower limit values are suggested to improve the quality of the spectral fit of solar simulated radiation and the irradiance maximum should be limited to the range in which dose reciprocity is known to be conserved.
Environment, Controlled Environmental Monitoring/methods Environmental Monitoring/standards Guidelines as Topic Models, Statistical* Photobiology/methods* Photobiology/standards* Radiation Dosage Radiometry/methods Radiometry/standards Reference Standards Reproducibility of Results Sensitivity and Specificity Solar Energy/standards* Spectrophotometry, Ultraviolet/methods* Spectrophotometry, Ultraviolet/standards* Ultraviolet Rays*