Replacing light sources and the need to determine the technical luminous coefficients

In this work, the authors present the necessity of photometric measurements in order to determine quality parameters when changing light sources with other types of light sources. To emphasize this we conducted a case study, measuring luminous parameters on two different streets, and we determined the technical luminous coefficients that establish the lighting system quality. We made photometric measurements on a street with sodium vapours lamps and on a street with LED lamps, determined the technical light parameters and did a comparison of the results. The outcome of the case study underline the need of conducting photometric measurements and of the lighting system redesign such that, upon changing the light sources and the technical characteristics of the lighting systems, the system still fulfils the technical standards requirements. In conclusion, for each space that is to be illuminated, an optimal solution should be found, which ensures both a reduction of the energy consumptions (reducing the system's costs) and meets the technical lighting requirements.