The transport properties of an amorphous polyamide, poly(trymethylhexamethylene terephtalamide) or Trogamid-T, were determined by different experimental methods. Sorption methods included two electrobalances, one for subatmospheric pressures and the other one up to 20 bar, and a pressure decay cell. Also, a permeability cell was used to measure permeability coefficients for pure gases and a gas mixture. The solubility, diffusion, and permeability coefficients calculated by different methods were in good agreement. With regard to permeability, measurements showed the difference between ideal and real permselectivity. Moreover, the results confirmed the good barrier properties of Trogamid-T. (c) 2006 Wiley Periodicals, Inc.