A differential mobility analyzer (DMA) and an aerodynamic aerosol classifier (AAC) are used in tandem to measure the effective density, dynamic shape factor, and mass of soot and dioctyl sebacate (DOS) particles. Soot particles were generated from an inverted burner. The mass-mobility exponent of the soot particles was determined to be 2.17. The effective density of soot decreases from 0.86 +/- 0.08 to 0.18 +/- 0.02 g/cm(3) over the range of 95-637 nm in mobility diameter and the shape factor increased from 1.51 +/- 0.06 to 2.62 +/- 0.10 over the same range. The effective density of the DOS particles was determined to be 0.903 +/- 0.90 g/cm(3) (which is within uncertainty of the material density of DOS), the mass-mobility exponent was 3.01, and the dynamic shape factor was 1.03 +/- 0.05, which illustrate the spherical shape of the DOS droplets. (C) 2014 Elsevier Ltd. All rights reserved.