This diploma thesis examines the calibration of the three different three-hole pressure probes, which are currently available on the institute. Three-hole pressure probes serve to measure the stationary velocities and their directions in two- dimensional flow field. With this particular type of pressure probes, measurements of velocity and direction are performed indirectly via the data about pressure. Before a probe can be used in practice, a calibration is required. For this purpose, the probe is put into a low-turbulence jet with a known constant velocity in a series of predefined angles. The various pressures measured at the holes serve as basis for the calculation of dimensionless calibration coefficients. Three-hole probes are used solely for operations in two- dimensional flow fields, which signifies that the pitch angle is equal to zero. In the blading of a turbomachine, though, the flow field is not constant. This leads to measurement errors caused by components of the velocity perpendicular to the yaw plane. This diploma thesis aims to analyse the effects of the pitch angle on the measurements resulting from the calibration of three-hole pressure probes. The data of the experiments that were carried out will be compared and interpreted according to the streamline projection method. Additionally, the SVUSS/3 Cobra-probe will be calibrated with a constant yaw angle and subsequently compared to the data which has been provided by the SVUSS company.