SIMPLE AND EFFECTIVE SUN SIMULATOR FOR LAI TEST
Sun simulator can provide a fixed and standard photo-environment for Leaf Area Index test experiments and researches, shielding from the influence caused by changes of time and space of exterior environment. However, the prevalent sun simulators possess lots of weakness such as high cost, the complexity of the structure and the unparallelism of the light. That is to say, the supply can never meet the demand. For solving the problems of framework complexity and high cost by sun simulator with certain parallelism, a simple but effective sun simulator was built, based on the principle of dispersion of light. With a serious consideration and validate test, xenon lamp was selected as the optical source and convex was selected as the device to generate the parallel light. Besides, the rest of the emulator will also contain the following parts: optical source and electronic elements such as transformer, trigger, high-voltage wire and bracket for light while the optical elements such as convex and lamp cup will be included in the emulator. In addition, the synchronous and U shaped bracket which connects the sensor and the sun simulator simultaneously will be counted in. After the analysis with SPSS, applying a method named S-N-K (which stands for Student-Newman-Keuls) the result manifests that (1) there is no apparent distinction between the sizes of areas of projection area of barrier chip at different heights and positions, proving that the parallelism is stable in the range of output of light in the lens sizes of area of the systems output when comes to the variance of size of projection area D of barrier chip (2) when comes to distinction of energy of projection P, covered by the same plane, which is a black body, the dispersion value will varies inversely with the height under the condition that H keeps constant, h2 is a variant (H stands for the distance between the lens and the sensor while h2 stands for the distance between the plane of the barrier chip and the sensor) (3) when comes to distinction of energy of projection P, the law of change of energy of dispersion light at the altitude of the sun: the dispersion varies directly with the altitude of the sun also exits (4) there is an obvious distinction between the existence and the non-existence of the barrier chips, which proves that energy of projected radiation is far greater than that of dispersive radiation. In a word, this sun simulator can fully meet the great demand of the experiment of testing LAI, proving the solid and validated data to the subsequent experiments.
sun simulator LAI zenon lamp convez direct radiation
Zhen Li Weibin Wu Tiansheng Hong Zili Zhang Yuqing Zhu
Key Laboratory of Key Technology on Agricultural Machine and Equipment (South China Agricultural University),Ministry of Education,Guangzhou 510642,China College of Engineering,South China Agricultural University,Guangzhou 510642,China
国际会议
北京
英文
1-8
2009-10-14（万方平台首次上网日期，不代表论文的发表时间）