This master's degree thesis is the project's report of the internship completed by the candidate at the Von Karman Institute for Fluid Dynamics in Rhode-Saint-Genèse, Belgium, between May 2024 and November 2024. During the internship a prototype of a high-speed, low-pressure turbine stage for a geared turbofan engine was mounted on the CT3 facility; this stage, designed by Safran Aircraft Engines, had previously been tested on the same facility of the Von Karman Institute (VKI) within the Clean Sky 2 project SPLEEN. The primary objective of this project is to accurately determine the rotor's actual inertia to validate the results of the SPLEEN project, aiming for a result that closely matches the value obtained from the CAD model, as well as aiming to a target uncertainty on all measurements around or less than 0.5%.