Radiometric characterization of the light sources was done with a UV light sensor (RM12 Sensor Opsytec Dr. Göbel UVA+), that could be placed at a known position relative to the light source, in a predefined grid. After the fixation of the sensor, proper shielding of the environment was ensured, whereafter the light source was turned on. The light intensity after stabilization of the value was noted. A dark experiment was conducted to account for any possible background irradiation.