Messtechnische Bewertung weißer LED-Leuchten

Since LEDs (Light Emitting Diode) become more and more important in general lighting, there is a growing demand for a thorough characterization of modern lamps and luminaires. Therefore, new measurement and presentation methods as well as technical key figures need to be developed. This thesis deals with the gonio-spectroradiometric measurement of the angular dependent spectral power distribution of phosphor-converted white LED luminaires. These luminaires show significant angular dependent colour shifts. The chosen measuring distance between the device under test and the spectroradiometer allows the display of the spectral behavior of the luminaires in far-field. Colour shifts on illuminated surfaces in real-life applications can be understood. For the evaluation of angular dependent colour shifts, threshold and tolerance values of previous research have been summarized and compared to the threshold values of current standardization for LED luminaires. Hence, application-specific threshold values for the object of study were derived. In order to present and evaluate the homogeneity of the spatial colour distribution, a two-dimensional Cartesian diagram is recommended which shows the maximal colour distance relating to the main beam direction depending on the spherical distance further allowing a spatial comprehension of the maximal colour distance. This diagram should be part of the technical datasheets of LED luminaires.