This part of ISO 14577 specifies the method of verification and calibration of testing machines for carrying out the instrumented indentation test in accordance with ISO 14577-1. It describes a direct verification method for checking the main functions of the testing machine and an indirect verification method suitable for the determination of the repeatability of the testing machine. The indirect method shall be used in addition to the direct method and for the periodic routine checking of the testing machine in service. The indirect method of verification of the testing machine shall be carried out independently for each test method. This part of ISO 14577 is also applicable for transportable testing machines.