37 Installation and repair of optical devices and equipment, electronic ballasts for LED lights and lighting fixtures, electronic ballasts for lighting purposes, ballast for the cassette with the illuminant as components of a lighting system as well as control unit, in particular measuring apparatus for measuring the irradiance in the range of UV light, measuring apparatus for measuring wavelengths in the range of UV light, measuring apparatus for measuring the UR intensity, measuring apparatus for measuring the UV dosage, resistance measuring apparatus for determining a change in resistance of a material when irradiated with UV light, measuring apparatuses for determining a radiation dose, computer hardware for controlling lighting systems for printing a surface in preparation for further process steps or modifying a surface structure, in particular with UV radiation, computer hardware for controlling lighting systems for hardening a surface in preparation for further process steps or modifying a surface structure, in particular with UV radiation, computer hardware for controlling lighting systems for sterilizing a surface or surface structure, in particular with UV radiation, computer hardware for controlling lighting systems for cleaning a surface for preparing further process steps or modifying a surface structure, in particular with UV radiation, computer hardware for controlling lighting systems for activating a surface for preparing further process steps or modifying a surface structure, in particular with UV radiation, cables and tubes for conducting electricity, electric cables, electronic cables, ultraviolet lamps, germicidal lamps, ultraviolet sterilization devices for water treatment, devices for ultraviolet sterilization of water for commercial purposes, illuminants for lighting systems for hardening, cleaning and activating a surface in preparation for further process steps or for modifying a surface structure, all the aforementioned steps in particular with UV radiation, illumination systems, in particular components of the illumination system being a cassette with the illuminant, the illuminant, cooling equipment, flash lamps, illumination systems and illuminants for illumination systems for sterilizing media, surfaces and fluids, illumination systems and illuminants for illumination systems in particular for emitting UV radiation; installation services, namely, installation of lighting systems and illuminants for lighting systems, in particular of UV lighting systems and illuminants for UV lighting