This paper demonstrates a simple method to enhance visibility through clean-burning flames that allows new opportunities to perform optical metrology in fire research. The method combines narrow-spectrum, blue illumination and matched optical filters to reduce the influence of optical emissions from a glowing hot target and a large natural gas diffusion flame. The paper describes how the required illumination strength and filtering can be estimated from basic combustion and optical principles. Compared to white light, the required illumination to detect objects engulfed in flames with this method is reduced by a factor of 104. A series of experiments are conducted to determine the effectiveness of this method, successfully demonstrating the ability to take images of objects in natural gas fires up to 1000 kW using 200 W of illumination power. These experiments corroborate the estimation of relative optical intensities, as it is observed that the target can be imaged successfully when the estimated signal-to-noise ratio exceeds 2:1. The temporal averaging of successive images is also demonstrated to further improve the image quality.

中文翻译：

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使用窄谱照明通过火成像

本文展示了一种通过清洁燃烧的火焰提高能见度的简单方法，为在火灾研究中进行光学计量提供了新的机会。该方法结合了窄光谱、蓝色照明和匹配的滤光片，以减少来自炽热目标和大型天然气扩散火焰的光发射的影响。该论文描述了如何从基本的燃烧和光学原理估计所需的照明强度和过滤。与白光相比，使用这种方法检测被火焰吞没的物体所需的照明减少了 104 倍。 进行了一系列实验来确定这种方法的有效性，成功证明了拍摄自然物体图像的能力燃气使用 200 W 的照明功率可产生高达 1000 kW 的功率。这些实验证实了相对光强度的估计，因为观察到当估计的信噪比超过 2:1 时，目标可以成功成像。还演示了连续图像的时间平均以进一步提高图像质量。