Abstract This study presents the development of a spatially resolved transmittance system for detecting internal rots in onions, particularly small and localised rots. A two-wavelength classifier was chosen by considering sensitivities to rots and path-length variations. Near-infrared spectroscopy transmittance measurements were carried out on rot-affected onions, to determine wavelength sensitivities to the presence and severity of rots. Finite Element simulations of light transport in onions were run to determine wavelength sensitivities to source-detector separation. A spatially resolved transmittance system was then developed, using two laser diodes as sources (728 and 805 nm wavelengths) and a single photodiode as detector. The system was experimentally verified, with the measured spatial profiles of the transmittance ratios of the two source wavelengths being sensitive to variation in position and size of internal rots in onions.

中文翻译：

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一种用于检测洋葱内部腐烂的空间分辨透射光谱系统

摘要 本研究提出了一种空间分辨透射系统的开发，用于检测洋葱的内部腐烂，特别是小而局部的腐烂。通过考虑对腐烂和路径长度变化的敏感性，选择了一个双波长分类器。对受腐烂影响的洋葱进行近红外光谱透射率测量，以确定波长对腐烂的存在和严重程度的敏感性。运行洋葱中光传输的有限元模拟以确定波长对源-检测器分离的敏感性。然后开发了空间分辨透射系统，使用两个激光二极管作为光源（728 和 805 nm 波长）和一个光电二极管作为检测器。该系统经过实验验证，