Abstract Number: 382 Working Group: Instrumentation and Methods
Abstract The APM (Aerosol Particle Mass Analyzer) can measure the effective density of particles by using a differential mobility analyzer (DMA) together, and furthermore, for example, the fractal dimension analysis and the evaluation of volatility of the particles have also been reported as the APM application studies. In this study, we confirmed the classification accuracy at high λc values by reducing the flow rate of APM such as 0.1 L/min, and checked the dependence of transmission efficiencies against particle diameter under the static operating condition. To clarify the classification accuracies of the APM for particle sizes below 30 nm, we firstly measured the particle size distributions classified by the APM to confirm the figures of transfer function, and then compared the number-averaged mass of the DMA-classified particles with the estimated particle mass from the DMA-classified diameter and the density of the test particles. This test was carried out under several operating conditions of the APM by setting a pair of different rotation speeds and flow rate for the same DMA-classified particles, and it was found that the measured masses of the DMA-classified particles were almost the same to the particles in spite of changing the APM operating conditions. It indicates that the APM can consistently operate to classify the particles according to the APM mass classification theory. Meanwhile, the gap between the measured and estimated particle mass as the particle size gets smaller was also reconfirmed for the range of particle sizes from 12 nm to 30 nm, and this difference expanded as the particle size decreased. In addition, we also investigated the transmission efficiencies of the APM based on the diffusion theory. For the differences of particle mass at the lower particle size range, we think that this reason should make clear but will be an issue in the future.