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New physical public nuisance survey and study

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The light pollution phenomenon becomes more obvious due to the increasing of installed lighting facilities and the new type of signboard made by LED arrays. It causes the negative influence to the environment and the human. Hence our research team got this project from Taiwan EPA to study the light pollution issue, including the standards and field survey of illuminance and luminance light pollution parameters. In the CIE (International Commission on Illumination) 150-2003 technical report there are four area category E1 natural area, E2 rural area, E3 suburban area and E4 urban area to describe the light pollution conditions. In this document there are 5 kinds of light pollution parameters, they are upper light ratio (ULR), luminous intensity (I), vertical illuminance (E), luminance (L) and threshold increment (TI), respectively. In our survey Czekh, Italy and USA use the luminous flux and luminous intensity to confine the light pollution. In Japan, they use five parameters as same as CIE to control the light pollution. In addition, they use type of usage including residential area, mixed residential and commercial area and commercial area, respectively. In Taiwan, we only use ULR to control the light pollution now, i.e. no suggested values of I, L, E and TI. In the field survey experiments, we use illuminance and luminance to study the current light pollution in Taiwan. There are 9 illuminance measurements and 27 luminance measurements, done in Hsinchu city and Taipei city. There are 8/9 exceed the CIE E4 suggestion value of 25 lx, only one test point below the E4 suggestion value but exceed it 1.14 lx with respective to the E3 10 lx suggestion. Totally of 19 self-emitted type signboard, there are 5 LED signboards among 15 LED type signboards exceed the E4 luminance suggestion 1000 cd/m2, i.e. 1/3 exceed the E4 suggestion value. For the fluorescent lamp (FL) type signboard, 4 measurements are all below the E2 luminance suggestion 400 cd/m2. There are 6 measurements of reflective type signboards, all of them are below the E2 suggestion value. In conclusion, both reflective type and FL type signboard have relative low light pollution influence to the LED type signboard. Hence, in the future control plan, the suggestion key point should focus on the LED type signboard. According to the measurement uncertainty study, in the low light pollution area, we suggest to use the single point measurement and get the time average value due to the low illuminance variation. On the other hand, in the high light pollution area due to high illuminance variation, we suggest to use grid-point measurements and get the average value. According to the measurement uncertainty study, due to the high variation of the content of LED type signboard, we recommend using single point measurement and get the time average value; while for the reflective type and FL type signboard, we recommend using grid-point measurement to get the average value due to the bad uniformity of the signboard.
Keyword
light pollution;vertical illuminance;luminance;upper light ratio;luminous intensity;LED type signboard
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