GB/T 21838.2-2022 "Metallic materials—Instrumented indentation test for hardness and materials parameters—Part 2: Verification and calibration of testing machines" specifies the direct and indirect verification methods for instrumented indentation testing machines. Direct verification is used to inspect the main functions, while indirect verification is applied to determine repeatability, which is suitable for portable testing machines. The installation of the testing machine must meet environmental and anti-vibration requirements, and the installation of the indenter holder should minimize the impact on overall compliance. The application and removal of test forces must avoid impact or vibration. Additionally, the standard regulates the relevant operational procedures for verification and calibration to ensure the reliability of test data.