In the following work permeability measurements for four different materials – one glass fibre twill-fabric and three carbon fibre non crimp fabrics (NCF) – were conducted. An optical and a capacity based method for measuring permeability, both available at LVV, were used and results compared. Additionally the influence of pressure on results was analyzed. For two materials, the results of capacity based measurements were compared to those obtained at IVW Kaiserlautern, using the same measurement device and software. Finally RTM experiments were conducted with manipulated performs, using the optical measuring device. Therefore parts of the standard performs were cut out and barriers of modeling clay or parts of other fabrics, used in this work, were introduced. PAM-RTM was used to carry out a simulation of the mentioned experiments and comparison was made for three of them. Generally permeability values obtained by the optical measuring device were about one order of magnitude higher than those of the capacity based method. It is suspected that this was due to compaction effects, for a correlation between pressure and permeability was detected for the optical method. Average standard deviation for the permeability results was found to be comparably low between three and 12,5%, while the optical method showed a more narrow distribution. Comparison with Kaiserslautern showed very good agreement for the glass fibre fabric, whereas results of the carbon fibre non crimp fabric showed considerable deviation especially at higher fibre volume fractions. RTM experiments and simulations were found to agree well for performs manipulated using modeling clay barriers. Due to race-trackig effects, for performs consisting of more than one fabric, it was not possible to simulate the experiments accordingly.