基于Mie散射原理, 提出了一种光度计与颗粒计数相结合的PM2.5颗粒质量浓度检测方法, 一定程度上减少了等效直径大于2.5μm的颗粒所产生的干扰。该方法利用655nm的激光器对悬浮颗粒物进行照射, 通过光电二极管接收Mie散射光强度, 并利用质心法统计分析出现概率最大的光强数据作为PM2.5颗粒所产生的真实散射光强度, 从而推断出PM2.5的质量浓度分布。最后, 将基于该方法与TSI公司生产的PM2.5检测仪在同一环境下进行对比, 发现测量误差显著降低, 在高浓度下测量误差仅±5μg/cm3。

Based on Mie scattering principle, a method for PM2.5 concentration detection was designed by combining photometer and particle counting, to some extent reducing the interference caused by the particles with the diameter equivalent to or larger than 2.5μm. It uses 655nm laser to irradiate on suspended particles, receives Mie scattering light intensity through the photodiode, and applies the centroid method to make statistical analysis on the light intensity data with the maximum probability, and then use it as the real scattering data generated by PM2.5 particles to deduce the distribution of PM2.5 mass concentration. Finally, compared with the PM2.5 detector produced by TSI company in the same environment, it is shown that using the proposed new method, the measurement error is significantly reduced, and it is reduced by only ±5μg/cm3 at high concentration of PM2.5.