Design and Application of an Unattended Multifunctional H-TDMA System

• 作 者: HAOBO TAN HANBING XU QILIN WAN FEI LI XUEJIAO DENG P.W.CHAN DONG XIA YAN YIN
• 机 构: Key Laboratory for Atmospheric Physics and Environment, Nanjing University of Information Science an
• 出 处: 广东省科协,香港工程师学会,澳门工程师学会
• 发表日期: 2014年12期

　　The hygroscopic properties of aerosols have a signi.cant impact on aerosol particle number size distri-butions (PNSD),formation of cloud condensation nuclei,climate forcing,and atmospheric visibility,as well as human health.To allow for the observation of the hygroscopic growth of aerosols with long-term accuracy,an unattended multifunctional hygroscopicity-tandem differential mobility analyzer (H-TDMA) system was designed and built by the Institute of Tropical and Marine Meteorology (ITMM),China Meteorological Administration (CMA),in Guangzhou,China.The system is capable of measuring dry and wet PNSD,hy-groscopic growth factor by particle size,and mixing states.This article describes in detail the working prin-ciples,components,and calibration methods of the system.Standard polystyrene latex (PSL) spheres with five different diameters were chosen to test the system s precision and accuracy of particle size measurement.Ammonium sulfate was used to test the hygroscopic response of the system for accurate growth factor mea-surement.The test results show that the deviation of the growth factor measured by the system is within a scope of-0.01 to-0.03 compared to K(o)hler theoretical curves.Results of temperature and humidity control per-formance tests indicate that the system is robust.An internal temperature gradient of less than 0.2 K for a second differential mobility analyzer (DMA2) makes it possible to reach a set-point relative humidity (RH) value of 90% and with a standard deviation of ± 0.44%,sufficient for unattended field observation.