"JJG 2005-1987 Brinell hardness tester verification system" is a standard issued by the National Measurement Bureau to standardize the verification procedures and requirements of Brinell hardness testers. The standard was approved on December 22, 1987 and implemented on October 1, 1988. The text specifies in detail the use, composition, Measurement characteristics and methods of verification of Brinell hardness tester reference and metrology standard appliances. At the same time, the standard also covers the Measurement characteristics of working measurement appliances to ensure their accuracy and reliability in practical applications. As an important part of the national Measurement verification system, the standard provides scientific basis and technical support for brinell hardness testing, which helps to improve the Measurement accuracy and conformity in related fields.