Measurement and test results are only trustworthy if in addition to the tested quality characteristics of products also the test equipment used for testing is regularly monitored and calibrated. The series of standards VDI/VDE/DGQ 2618 provides the necessary instructions for the monitoring of test equipment for dimensional measurements. The standard thus provides a basis for the monitoring of inspection equipment, the both in-house and cross-operation can be applied. The revised standard VDI/VDE/DGQ/DKD 2618 Part 10.8 lays down the inspection scope for internal micrometers with three-line contact in a table by means of directly applicable action and work instructions. The standard applies in conjunction with VDI/VDE/DGQ 2618 Part 1.1 and VDI/VDE/DGQ 2618 Part 1.2.