Abstract: A system for measuring an internal dimension, such as the radius, of a cylindrical cavity over a determined length, particularly in a hollow shaft belonging to a turbomachine. The system includes a measurement module mounted removably on a support that has translational mobility inside and along the axis of the cavity, the module including a measurement component for measuring the dimension and delivering signals corresponding to the measured values and incorporating a recording and storage for recording and storing the values. More particularly, the module includes a mechanical sensor component able to move between a retracted position and an extended position for sensing the internal surface of the cavity.

Abstract: The present invention relates to a system for measuring an internal dimension, such as the radius, of a cylindrical cavity over a determined length, particularly in a hollow shaft (1) belonging to a turbomachine. The system is one which comprises a measurement module (40) mounted removably on a support that has translational mobility inside and along the axis of the cavity, the module (40) comprising a measurement component (43) for measuring the dimension and delivering signals corresponding to the measured values and incorporating a recording and storage means (461) for recording and storing said values. More particularly, the module (40) comprises a mechanical sensor component (43) able to move between a retracted position and an extended position for sensing the internal surface of the cavity. The system applies in particular to checks on the boring-out of the internal cavity of a turbomachine shaft.