UV source for irradiation of the sunscreen sample
The spectral irradiance at the exposure plane of the artificial UV source (used for ir-radiation of the sunscreen sample) should be as similar as possible to the irradiance at ground level under a standard zenith sun as defined by COLIPA (1994) or DIN 67501 (1999). The UV irradiance must be within the following acceptance limits (measured in the same plane as the sunscreen sample):