Comparison of Measurement Uncertainty Evaluation of New and Old Brinell Hardness National Standards for Metallic Materials

The evaluation methods of measurement uncertainty in GB/T 231. 1-2009 and GB/T 231. 1-2018 were compared and analyzed. The measurement uncertainty of Brinell hardness of Cr12MoV steel and standard sample was calculated by using the measurement uncertainty evaluation method in the new and old standards. The results show that the method in the 2018 version standard could obtain relatively accurate measurement uncertainty compared with the method in the 2009 version. The measurement uncertainty of method M2 was smaller than that of method M1.