Transpiration evaporation experiments are often used to study evaporation kinetics from liquids or melts. The mass transport of volatile species in a transpiration experiment depends among others on the flow conditions of the carrier gas in the tube and on the geometrical configuration. For a transpiration test set-up, CFD modelling showed to be an excellent tool to predict the mass transport of volatile species into a carrier gas and to understand the fluid dynamics in the gas phase and distribution of volatile species in this phase. Relatively simple mass transport relations were obtained for a fixed geometry of the transpiration test setup. These relations proved to be also applicable for different volatile species and different temperature ranges. (c) 2005 Elsevier Ltd. All rights reserved.