School of Electronic Information and Communications, Huazhong University of Science and Technology, Wuhan 430074, China.
Hubei Key Laboratory of Smart Internet Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Biosensors (Basel). 2022 Jun 21;12(7):436. doi: 10.3390/bios12070436.
Mass concentration is a commonly used but insufficient metric to evaluate the particulate matter (PM) exposure hazard. Recent studies have declared that small particles have more serious impacts on human health than big particles given the same mass concentration. However, state-of-the-art PM sensors cannot provide explicit information of the particle size for further analysis. In this work, we adopt Sauter mean diameter (SMD) as a key metric to reflect the particle size besides the mass concentration. To measure SMD, an effective optical sensing method and a proof-of-concept prototype sensor are proposed by using dual wavelengths technology. In the proposed method, a non-linear conversion model is developed to improve the SMD measurement accuracy for aerosol samples of different particle size distributions and reflective indices based on multiple scattering channels. In the experiment of Di-Ethyl-Hexyl-Sebacate (DEHS) aerosols, the outputs of our prototype sensor demonstrated a good agreement with existing laboratory reference instruments with maximum SMD measurement error down to 7.04%. Furthermore, the simplicity, feasibility and low-cost features of this new method present great potential for distributed PM monitoring, to support sophisticated human exposure hazard assessment.
质量浓度是评估颗粒物（PM）暴露危害的常用但不充分的指标。最近的研究表明，对于相同的质量浓度，小颗粒比大颗粒对人类健康的影响更为严重。然而，最先进的 PM 传感器无法提供有关粒径的明确信息，无法进一步分析。在这项工作中，我们采用 Sauter 平均直径（SMD）作为除质量浓度之外的关键指标来反映粒径。为了测量 SMD，我们提出了一种有效的光学传感方法和一种基于双波长技术的概念验证原型传感器。在提出的方法中，开发了一种非线性转换模型，以提高基于多散射通道的不同粒径分布和反射指数的气溶胶样品的 SMD 测量精度。在 Di-Ethyl-Hexyl-Sebacate（DEHS）气溶胶的实验中，我们的原型传感器的输出与现有的实验室参考仪器具有很好的一致性，最大 SMD 测量误差低至 7.04%。此外，这种新方法的简单性、可行性和低成本特点为分布式 PM 监测提供了巨大的潜力，以支持复杂的人类暴露危害评估。
