Gafchromic external beam therapy 3 (EBT3) film has widely been used in medical field applications. Principally, the EBT3 film’s color gradually changes from light green to darker color under incremental exposures by ionizing or even non-ionizing ultraviolet (UV) radiation. Peak absorbance of the EBT3 film can be used to predict absorbed doses by the film. However, until today, related researches still rely on spectrometers for color analysis of EBT3 films. Hence, this paper presents a comparative analysis between results produced by the spectrometer and a much simpler light-emitting diode-photodiode based system in profiling the color changes of EBT3 films after exposure by solar UV radiation. This work has been conducted on a set of 50 EBT3 samples with incremental solar UV exposure (doses). The wavelength in the red region has the best sensitivity in profiling the color changes of EBT3 films for low solar UV exposure measurement. This study foresees the ability of blue wavelength to profile films with a large range of solar UV exposure. The LED (light emitting diode)-based optical system has produced comparable measurement accuracies to the spectrometer and thus, with a potential for replacing the need for a multipurpose spectroscopy system for simple measurement of light attenuation.

中文翻译：

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光谱和基于发光二极管的系统表征用于太阳紫外线测量的外照射疗法3膜

全色外照射治疗3（EBT3）膜已广泛用于医疗领域。原则上，在通过电离或什至非电离紫外线（UV）辐射进行增量曝光后，EBT3膜的颜色逐渐从浅绿色变为较暗的颜色。EBT3膜的峰值吸收率可用于预测膜的吸收剂量。但是，直到今天，相关研究仍依赖光谱仪对EBT3膜进行颜色分析。因此，本文将对光谱仪和基于简单得多的发光二极管-光电二极管的系统产生的结果进行比较分析，以分析太阳紫外线照射后EBT3膜的颜色变化。这项工作是针对一组50个EBT3样品进行的，这些样品具有递增的太阳紫外线暴露（剂量）。红色区域中的波长在分析EBT3膜的颜色变化以进行低日照度紫外线照射时具有最佳灵敏度。这项研究预见了蓝色波长能够在大范围的紫外线照射下使薄膜轮廓化。基于LED（发光二极管）的光学系统已经产生了与光谱仪相当的测量精度，因此，有可能取代对用于简单测量光衰减的多功能光谱系统的需求。