ultraviolet protection factor
measurement of the protective quality of a fabric sample against solar ultraviolet radiation, determined by in-vitro testing
Note 1 to entry: For in-vitro testing the erythemal irradiance measured by a detector with the fabric sample under test in place is compared to the erythemal irradiance measured with no fabric present, where the source is typically a solar simulator. This is expressed as the quotient of the erythemal irradiance without fabric and the erythemal irradiance through fabric:
Note 2 to entry: The ultraviolet hazard spectral weighting function,
Note 3 to entry: The ultraviolet protection factor has unit one.
Note 4 to entry: This entry was numbered 17-1366 and 17-1377 in CIE S 017:2011.