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Technology and Engineering
- ISSN: 2333-2581
- Modern Environmental Science and Engineering
A Brand New World: Impacts Study of the Background
Luminance and Illumination Level on Measuring of LED
Billboards in Taiwan
Bao-Jen Pong1*, Chao-Hua Wen1, Shao-Tang Hung1, Shao-Tang Hung1, Zheng-Lin He2, Mang Ou-Yang2, and
Kuei-Neng Wu1
1. Industrial Technology Research Institute/Center for Measurement Standards, Hsin-Chu, Taiwan
2. Department of Electrical and Computer Engineering, National Chiao Tung University, Hsinchu, Taiwan
Abstract: Based on the domestic conditions of Taiwan, this study aims to investigate and analyze the impacts of statutory nuisance from artificial light, and then to propose the related tactics and recommendations. Our research focuses on both perception of glare and flicker. The main tasks include: (1) measurements of light pollution source, (2) study on the borderline between comfort and discomfort (BCD) of human perception and cognitions to perform subjective evaluation of glare and flicker at night condition, (3) case study of the background luminance and illumination level impacts on measuring resultants of nuisance artificial light (e.g., LED billboard). In this work, we will discuss the third task only.
This study conducted a total of 4 case studies of monitoring the luminance of LED billboards, vertical and horizontal illuminance in Taipei metropolitan area and Hsinchu downtown area.
The maximum luminance of LED billboards are between 1,588 cd/m2 and 3,029 cd/m2, the maximum vertical illuminance at 4 measuring locations are between 17.6 lx and 96.7 lx, the maximum horizontal illuminance at 4 measuring locations are between 5.1 lx and 72.2 lx.
The minimum luminance are in the range of 0.1 cd/m2 to 0.7 cd/m2, while the minimum vertical illuminance at 4 measuring locations are in the range of 0.2 lx to 35.2 lx, the minimum horizontal illuminance at 4 measuring locations are between 2.0 lx and 50 lx.
The Michelson contrast modulation (Cm) of vertical illuminance at 4 measuring locations are between 49.6% and 99.3%, while the Cm of horizontal illuminance at 4 measuring locations are between 47.1% and 94.7%.
The minimum luminance is the sum of other light sources project on the turn-off LED billboard, said the background luminance, it is no impact on the luminance measuring of LED billboard. From the Michelson contrast module of vertical illuminance at 4 locations, indicated the vertical illuminance is strong influence by the environment lighting condition. The minimum vertical illuminances are separated into two groups, one is below 25 lx, and another one is above 25 lx. This result can be used as the reference classification of night time lighting environment of urban area (non-metropolitan area) and metropolitan area of Taiwan.
Key words: light pollution, background illuminance, LED billboard
