GB/T 38243-2019 "Rubber — Inspection and calibration of hardness testers" was issued in October 2019 and implemented in May 2020. It is identical to the international standard and applies to the inspection and calibration of various Shore hardness testers (such as Type A and Type D), as well as rubber international hardness testers and ultra-soft rubber hardness testers. The standard specifies an ambient temperature requirement of 18°C to 25°C, defines key inspection items and tolerances such as the geometric dimensions of the indentor, the specifications of the presser foot, the extension of the indentor, and the test force, and clarifies the corresponding measurement methods and inspection point requirements. It also standardizes the content of inspection and calibration certificates, providing a unified technical basis for the quality control of rubber hardness measuring instruments, thereby ensuring the accuracy and consistency of hardness test results.