Enables illuminance to be measured with CASSY (5210.524013, 5210.524006, 5210.524009A, 5210.524018) or the universal chemistry measuring instrument (5210.531836). Depending on the sensor, the illuminance can be measured in lux or the irradiance in W/m² in various spectral ranges (UV-A, UV-B, UV-C, Vis, IR, IR-CO2).