Abstract: The uncertainty of measurement of total loss of silicon steel sheet, including the components of the result repeatability, the weight measurement and the length measurement, was evaluated by the evaluation method of class A and class B uncertainty components on the basis of the mathematical model of the measurement of total loss of silicon steel sheet by Epstein frame method. Finally, the extended uncertainty was calculated and the uncertainty report was generated. 

Key words: Epstein frame method, silicon steel sheet, uncertainty, total loss