ISO 4545-2:2017规定了用于根据ISO 4545-1确定金属材料的努氏硬度的测试机器的验证和校准方法。 为测试机，压头和对角线长度测量系统指定了一种直接的校验和校准方法。为机器的整体检查指定了使用参考块的间接验证方法。 如果测试机器也用于其他硬度测试方法，则将针对每种方法独立验证测试机器。

ISO 4545-2:2017 specifies the method of verification and calibration of testing machines for determining Knoop hardness for metallic materials in accordance with ISO 4545‑1. A direct method of verification and calibration is specified for the testing machine, indenter, and the diagonal length measuring system. An indirect verification method using reference blocks is specified for the overall checking of the machine. If a testing machine is also to be used for other methods of hardness testing, it will be verified independently for each method.