IEC TR 62981:2017

FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 Background
5 Preliminary comparisons and experiments
6 International comparison of SST measurements
  on grain-oriented electrical steel and accompanying
  Epstein measurements
7 Summary and conclusions
Bibliography

IEC TR 62981:2017(E), which is a Technical Report, provides the results of international exercises and comparisons focusing on achieving the knowledge of the statistical performance of single sheet tester (SST) measurements made on grain-oriented electrical steel. These experiments aim at specifying obligatory reference values, measured by the single sheet test method, for the grading of high permeability (P grades) grain-oriented (g.-o.) materials, independently from the Epstein classification as it is practiced today. Besides this, Epstein test measurements have been made in order to gain more up-to-date statistical performance for comparison with the SST statistical characteristics. A few experiments were carried out aiming at improved knowledge on the systematic error performance of the SST, i.e. they were to determine the correlation between the quality of insulation separating laminations in the SST yokes and the measured loss.