GB/T 18449.2-2001 in English

《GB/T 18449.2-2001金属努氏硬度试验 第2部分:硬度计的检验》由TC122（全国试验机标准化技术委员会）归口，主管部门为中国机械工业联合会。
本标准规定了按GB/T 18449.1测定金属材料努氏硬度用的努氏硬度计的检验方法。硬度计的最大试验力为9.807N。本方法仅适用于长对角线长度不小于20μm的压痕。
本标准描述了检验硬度计基本功能的直接检验法和适用于硬度计综合检验的间接检验法。间接检验法可独立地用于使用中的硬度计的定期常规检查。如果硬度计还可用于其他方法的硬度试验，则应分别按每一种方法单独地对硬度计进行检验。

Scope

This standard specifies the inspection method of the Knoop hardness tester used to determine the Knoop hardness of metal materials according to GB/T 18449.1. The maximum test force of the hardness tester is 9.807N. This method is only applicable to indentations whose long diagonal length is not less than 20 μm. This standard describes the direct test method for checking the basic functions of hardness testers and the indirect test method suitable for the comprehensive test of hardness testers. The indirect test method can be used independently for regular routine inspection of hardness testers in use. If the hardness tester can also be used for hardness testing by other methods, the hardness tester shall be tested separately according to each method.