With the aid of the theoretical relationship between the calibration relation of a SEC column for the monodisperse polymer species under ideal working condition and the effective relations between the molecular weight and the elution volume for characterized polymer samples

a computational procedure for simultaneous calibration of molecular separation and column dispersion is proposed. From the experimental chroma-tograms of narrow MWD polystyrene standards and broad MWD 1

2-polybutadiene fractions the spreading factors of a SEC column was deduced by the proposed method. The variation of the spreading factor with the elution volume is independent of the polymer sample used.