The electrical resistivity of an α-CuZn alloy containing 30 at.% Zn has been measured on-line during 3 MeV electron irradiation at temperatures between 299 K and 435 K. Negative resistivity changes due to short range ordering have been observed. For temperatures above 350 K stationary resistivity values, i.e. equilibrium states of short range order were achieved, which show a linear dependence on temperature. The relaxation rates which were determined from the resistivity kinetics are compared to those from resistivity and Zener relaxation experiments in the literature as well as to model calculations of the defect concentrations.