ISO 18872:2007 specifies procedures for determining the tensile properties of moulding and extrusion plastics over a wide range of strain rate, including high rates appropriate to impact-loading situations. Properties are determined through a combination of measurements at low and moderate strain rates, the use of mathematical functions to model these results, the rate-dependence of parameters and the determination of parameters at high strain rates by extrapolation. Tensile properties at high strain rates are then derived by calculation. In this way, the experimental problems and associated errors with the measurement of properties at high rates are avoided.