Chen Ang, Wang Shu, Liu Youjiang, Yan Shu, Zeng Jin, Deng Tian
School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan 430074, China.
State Key Laboratory of Transducer Technology, Hefei Institute of Intelligent Machines, Chinese Academy of Sciences, Hefei 230031, China.
ACS Sens. 2020 Jul 24;5(7):2061-2066. doi: 10.1021/acssensors.0c00574. Epub 2020 Jul 14.
Aerosol plays an important role in a broad range of scientific disciplines, such as atmospheric chemistry and physics, fuel combustion, and human health. Current particle sizing instruments are usually bulky, complicated, and expensive, while the portable ones cannot provide sufficient measurement channels to describe the particle size distribution accurately. To address this challenge, we propose an optical sensing method to analyze the particle size distribution of aerosols based on the light scattering intensity field (LSIF). The LSIF is a set of scattering lights in all directions around the particles, which contains the scattering light signals in different observing angles. Then, the particle size distribution of the aerosol samples is retrieved by the Tikhonov regularization algorithm. A portable and low-cost aerosol sizing prototype sensor is designed to image part of the LSIF signals, where the LSIF is collected by a parabolic reflector and projected on the image sensor as an image with telecentric lenses. According to the experimental result of di-ethyl-hexyl-sebacate aerosol test, the relative measurement error of LSIF can be controlled to ±10%. With an integrated and cost-effective design, this particle sizing sensor shows great potential for routine field measurements outside of the laboratory.
气溶胶在广泛的科学学科中发挥着重要作用，如大气化学与物理学、燃料燃烧以及人类健康等领域。当前的颗粒大小测量仪器通常体积庞大、结构复杂且价格昂贵，而便携式仪器又无法提供足够的测量通道来准确描述颗粒大小分布。为应对这一挑战，我们提出一种基于光散射强度场（LSIF）分析气溶胶颗粒大小分布的光学传感方法。LSIF是围绕颗粒在所有方向上的一组散射光，其中包含不同观测角度下的散射光信号。然后，通过蒂霍诺夫正则化算法反演气溶胶样品的颗粒大小分布。设计了一种便携式低成本气溶胶粒径测量原型传感器，用于对部分LSIF信号进行成像，其中LSIF由抛物面反射镜收集，并通过远心透镜作为图像投影到图像传感器上。根据癸二酸二异辛酯气溶胶测试的实验结果，LSIF的相对测量误差可控制在±10%以内。这种颗粒大小测量传感器采用集成且经济高效的设计，在实验室外的常规现场测量中显示出巨大潜力。
