Department of Civil Engineering, Korea National University of Transportation, Chungju 27469, Republic of Korea.
School of Architecture, Kumoh National Institute of Technology, Gumi 39177, Republic of Korea.
Sensors (Basel). 2023 Jul 6;23(13):6199. doi: 10.3390/s23136199.
With the increasing need for particulate matter (PM) monitoring, the demand for light-scattering sensors that allow for real-time measurements of PM is increasing. This light-scattering method involves irradiating light to the aerosols in the atmosphere to analyze the scattered light and measure mass concentrations. Humidity affects the measurement results. The humidity in an outdoor environment may exist as gas or steam, such as fog. While the impact of humidity on the light-scattering measurement remains unclear, an accurate estimation of ambient PM concentration is a practical challenge. Therefore, this study investigated the effects of humidity on light-scattering measurements by analyzing the variation in the PM concentration measured by the sensor when relative humidity was due to gaseous and steam vapor. The gaseous humidity did not cause errors in the PM measurements via the light-scattering method. In contrast, steam humidity, such as that caused by fog, resulted in errors in the PM measurement. The results help determine the factors to be considered before applying a light-scattering sensor in an outdoor environment. Based on these factors, directions for technological development can be presented regarding the correction of measurement errors induced by vapor in outdoor environments.
随着对颗粒物（PM）监测的需求不断增加，对能够实时测量 PM 的光散射传感器的需求也在增加。这种光散射方法涉及向大气中的气溶胶照射光线，以分析散射光并测量质量浓度。湿度会影响测量结果。户外环境中的湿度可能以气体或蒸汽的形式存在，例如雾。虽然湿度对光散射测量的影响尚不清楚，但准确估计环境 PM 浓度是一个实际挑战。因此，本研究通过分析当相对湿度由气态和蒸汽蒸气引起时传感器测量的 PM 浓度的变化，研究了湿度对光散射测量的影响。气态湿度不会通过光散射法对 PM 测量造成误差。相比之下，蒸汽湿度（例如雾引起的湿度）会导致 PM 测量出现误差。研究结果有助于确定在户外环境中应用光散射传感器之前需要考虑的因素。基于这些因素，可以提出针对室外环境中蒸气引起的测量误差进行修正的技术发展方向。
