In the laboratory, for determining the intrinsic permeability of the pulverulent medium, water was previously used as liquid penetrates the sample material to be studied. This method is widely used for materials with high porosity, high permeability such as soil, sand or gravel. However, this method is not really effective with materials high impermeability by long time experiments, complex laboratory equipment, and mainly expensive. Comparing with liquid, gas penetration is higher osmotic. Therefore, for overcoming this situation, in the cas of concrete material, an inert gas flow was used to penetrate the sample. The evaluation of the errors of the experimental results is a basis element to review what factors playa decisive role, thus generating measures to improve the accuracy, ameliorate instruments and. experimental procedures.