光腔光谱方法气溶胶消光系数比对测量

搭建了非相干宽带腔增强吸收光谱(IBBCEAS)实验装置,旨在实现大气气溶胶宽波段消光系数的在线测量。为评估IBBCEAS系统测量大气气溶胶消光系数的稳定性和准确性,联用单波长腔衰减相位移反照率监测仪(CAPS-ALB)在复旦大学环境科学楼开展比对测量研究。比对结果显示,两台装置在532nm波长处测量的气溶胶消光系数变化趋势基本一致,相关系数为0.974,说明IBBCEAS装置具有与通过计量检测认证的高精准度仪器相似的稳定性和可靠性。通过CAPS-ALB仪器的比对校准,IBBCEAS装置的测量平均偏差由7.08Mm^-1降低到2.4Mm^-1,测量准确性得到显著提升。另外发现,宽波段光谱测量对研究气溶胶消光系数的波长依赖性具有重要意义。

Intercomparison of Aerosol Extinction Measurement Based on Optical Cavity Spectroscopy

To achieve the on-line measurement of the broad-band extinction coefficient of atmospheric aerosols, an incoherent broad-band cavity enhanced absorption spectroscopy (IBBCEAS) experimental instrument was established. Then, in order to evaluate the accuracy and stability of the system, a comparative measurement was carried out simultaneously with CAPS-ALB, a single wavelength Cavity Attenuation Phase Shift ALBedo monitor, in the Environmental Science Building of Fudan University. The comparison result show that the measured aerosol extinction coefficients at the wavelength of 532nm of above two instruments has a same trend with a correlation coefficient of 0.974, indicating the established IBBCEAS system has similar reliability and stability to the metrological certificated high-precision instrument. After calibrated with CAPS-ALB, the measurement accuracy of the IBBCEAS system was significantly improved, and the measurement differency between the two instruments was reduced from 7.08Mm^-1 to 2.4Mm^-1. And it was also found that the broad-band spectral measurement is of great significance for studying the wavelength dependency of aerosol extinction coefficient.