ISO 6508-3:2015规定了用于洛氏硬度试验机间接和日常验证的参考试块的校准方法，如ISO 6508-2:2015所述。 需要注意的是，球压头使用硬质金属被认为是洛氏压头球的标准类型。只有符合ISO 6508‑1:2015附录A的要求，才能使用钢压头球。

This document specifies a method for the calibration of reference blocks to be used for the indirect and daily verification of Rockwell hardness testing machines and indenters, as specified in ISO 6508-2. This document also specifies requirements for Rockwell machines and indenters used for calibrating reference blocks and specifies methods for their calibration and verification. Attention is drawn to the fact that the use of hard metal for ball indenters is considered to be the standard type of Rockwell indenter ball.