The Process By Solvent Evaporation (PBSE) is one of the growth techniques recently developed to grow large size CdTe crystals from Te-rich CdTe solutions. The control of this solvent evaporation driven technique requires a precise knowledge of the amount of Cd and Te that are evaporated throughout the whole process: during heating up, isothermal evaporation and cooling down. We report on the experimental determination of these amounts and their exploitation in order to locate precisely the growth solution in the phase diagram, which allows us to develop a phenomenological model. We use this model in order to understand the behaviour of different solutions depending on their initial composition. These results lead to a more precise knowledge of the phase diagram in the range of our growth temperature and to an improvement of the plate singularity. (C) 2011 Elsevier B.V. All rights reserved.