Design and Performance Evaluation of a Low Pressure Impactor for Sampling Submicron Aerosols

서브마이크론 입자 측정용 저압 임팩터의 설계 및 성능평가

  • 지준호 (연세대학교 나노과학기술연구단) ;
  • 조명훈 (연세대학교 대학원 기계공학과) ;
  • 배귀남 (한국과학기술원 대기자원연구센터) ;
  • 황정호 (연세대학교 기계공학과)
  • Published : 2004.03.01


A low pressure impactor is an impaction device to separate airborne particles into aerodynamic size classes at low pressure condition. We designed a two-stage low-pressure impactor to classify submicron sized environmental aerosols. Performance evaluation was carried out for stages 1 and 2 by using an electrical method. Monodisperse liquid dioctyl sebacate (DOS) particles were generated using evaporation-condensation process followed by electrostatic classification using a DMA (differential mobility analyzer). The test particles were in the range of 0.08∼0.8$\mu\textrm{m}$. For the evaluation of the impactor we used two electrometers; one was connected to the impaction plate of the impactor and the other was to the Faraday cage used as a backup filter. The effect of polydispersity of test aerosols on the performance was investigated. The results showed that the experimental 50-% cutoff diameters at each impactor's operation pressure were 0.53 and 0.187$\mu\textrm{m}$ for stages 1 and stage 2, respectively. The effects of operation pressure on the cutoff diameter and the steepness of collection efficiency curves were also investigated.


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