Abstract Number: 162 Working Group: Instrumentation and Methods
Abstract The authors have proposed the centrifugal filter which has a tunable collection efficiency by changing the rotation speed of the filter without increasing the pressure drop. In the present work, the centrifugal filter was applied to classify aerosol particles followed by the detection of total mass or number concentrations so that we can continuously measure the size distribution of aerosol particles. The structure and operating condition of centrifugal filter were optimized in order to attain sharp separation curves with various cut-off sizes between 0.3 and 5 micro-meters. The aerosol penetrating the centrifugal filter at various rotation speeds was measured with a photometer to determine the total mass concentration (it is also possible to use a condensation particle counter when the centrifugal filter is applied to nanoparticles). The virtue of this system is such that the cut-off size is varied just by scanning the rotation speed of filter and that it can be applied to the measurement of high concentration aerosols without dilution by choosing an appropriate filter medium. We found that the centrifugal filter can achieve sharp separation curves which are comparable to a cascade impactor and it can continuously measure the change in size distribution of high concentration aerosols.