IEC/TR 62581:2010(E) describes the general principles and technical details of the measurement of the magnetostriction of single sheet specimens preferably 500 mm long and 100 mm wide and Epstein strip specimens, specified in IEC 60404-2, of electrical steel by means of optical sensors and accelerometers. These methods are applicable to test specimens obtained from electrical steel sheets and strips of any grade. The characteristics of magnetostriction are determined for a sinusoidal induced voltage, for specified peak values of magnetic polarization and for a specified frequency. The measurements are made at an ambient temperature of 23 °C +/- 5 °C on test specimens which have first been demagnetized.