Characterization of Spectroradiometric Based Luminous Flux Measurements for LED Luminaires at BRIN Indonesia

Abstract

Light Emitting Diode (LED) luminaires are known to have higher efficacy compared to other types of light sources. Therefore, this type of luminaire has been deployed to replace existing conventional types of light sources as means of energy-saving around the world. LED efficacy is commonly measured using a photometer mounted in a goniophotometer or an integrating sphere system. However, due to the different spectral properties of the LEDs compared with the source used in the photometer calibration, mismatch correction needs to be applied in the measurement process. Due to the arduous process of obtaining the correction, the measurement of luminous flux using a spectroradiometer is proposed in this study. By utilizing this device, the mismatch correction does not need to be applied. The measurements of several commercially available LED and energy-saving compact fluorescent luminaires (CFL) show that current LED has twice the efficacy of the CFLs. The LED shows efficacy in the range of 114 lumen/watt. The measurement uncertainty associated with the efficacy of the LED is 4.2%. It is expected that the quality assurance and the accuracy of LEDs luminaires measurement and testing in Indonesia can be improved by using the integrating sphere with the spectroradiometer measurement method.