Although extremely important in the world of science, turbulence is one of the least described physical phenomena. In the world of turbomachinery, it represents an area of great importance to researchers in academia and industry worldwide. Turbulent swirling structures occur inside the fan’s impeller, as well as on its discharge and suction sides. To describe this phenomenon, it is necessary to measure the velocity field in the areas of interest. Various measurement methods are used for this, but PIV and LDA stand out as the most modern non-invasive methods. Taking into account that the mentioned flow must be considered as three dimensional, composed form three components it further complicates the measurement. From a technical point of view, the conduction of these experiments represents a very complex and challenging task. This is a great challenge, especially for the measurements inside the impeller.