C-Plane Angular Interval Optimization for Accurate Photometric Measurement of LED Luminaires with Various Light Distributions

This study presents a measurement and comparative analysis of the photometric characteristics of two LED luminaires with different light distribution types, evaluated at varying $C$-plane angular intervals. Photometric data were obtained using goniophotometric measurements and are presented in both tabular and graphical formats. The tested luminaires include a road LED luminaire with axial light distribution symmetry and an industrial high-bay LED luminaire with rotational symmetry. Road lighting design calculations were also performed using specialized software to assess the impact of $C$-plane angular intervals on the calculated lighting and geometric parameters of the LED lighting system. The results emphasize the importance of selecting appropriate $C$-plane angular intervals in photometric measurements to balance accuracy and measurement time.