Evolution of the Particle Size Distribution of Mainstream Cigarette Smoke During a Puff

Abstract

Abstract A procedure for the measurement of the particle size distribution of minimally aged undiluted mainstream cigarette smoke is presented. The angular dependence of scattered light intensity was measured and a best fit log normal distribution was determined by comparison of ratios of the scattering intensities to theoretically calculated values. The problem of multiple scattering by the concentrated mainstream smoke was overcome by aerodynamically focusing the sampled smoke to a fine stream in a specially designed photometer. The photometer required no dilution of the smoke and performed the measurement on smoke aged 0.12 s, minimizing coagulation. Size distributions were determined at 100 points during a 2-s puff revealing significant changes in the average diameter of the aerosol during the puff. The changes in particle size are shown to correlate with the changing flow profiles in the cigarette during the smoking process.