Starting from three aspects, the paper introduces the reason and effects of glare and displays a kind of Unified Glare Rating(UGR) measuring system. Our research is dependent on the standard made by CIE and the UGR formula put forward by Sorensen, make use of digital camera, programming and digital image processing and develop a set of UGR measuring system. After testing, we find it able to measure indoor UGR and get repeatable results, which are close to the examples in CIEll7—1995 technical report. Hopefully, what the paper introduces can promote the implement of UGR standard and be avail to the simplification of the process of lighting quality evaluation.
This study focuses on the theory, construction and the performance measurement of a spectral-tunable LED light source. The light source is mainly combined by the LED illumination body, the spectral matching module as well as LED control driver module. The LED illumination includes thousands of high power LEDs across the whole visible spectral region. The received iterated data are allocated via LED data distribution card to drive LEDs on the illumination body, and precisely control the current of each LED by PWM（Pulse Width Module）, to achieve 256 and above gray scale illumination. Through the study, the spectral-tunable light source with size of 3 by 1.5 square meter including 1700 LEDs has been constructed and the optical performance has been tested. The white light with color temperature of 5000K is taken as the simulation target. The results show that the optical performance such as luminous flux and color temperature are gradually stabilized, which differ due to the LED type. The spectrum distribution is not so accurate to the target one. And some methods to minimize the difference are discussed as well.