A numerical comparison of different methods for determining the particle formation rate.

Different methods of determining formation rates of 3nm particles are compared, basing on analysis of simulated data, but the results are valid for analyses of experimental particle size distribution data as well. The study shows that the method of determining formation rates indirectly from measured number concentration data of 3-6nm particles is generally in good agreement with the theoretical calculation with a systematic error of 0-20%. While this is often accurate enough, a simple modification to the approximative equation for the formation rate is recommended. Additionally, the temporal connection between the concentration of the nucleating vapour and the formation rate is studied. It is concluded that the often used power-law connecting these two is inaccurate. [ABSTRACT FROM AUTHOR]