The directional sensitivities of the DISA Type 55P61 crossed-wire probe and DISA Type 55P91 gold-plated triple-wire probe were investigated using a modified calibration set-up with three very accurate orthogonal axes of rotation. The yaw factor k_T and pitch factor k_N which account for the cooling effects of tangential and binormal velocity components respectively were determined at different yaw angle a and pitch angle theta at velocities of 6 m s^-1, 11 m s^-1 and 19 m s^-1. Based on these measured values, the relative errors in the calculated flow velocity were computed with constant values of k_T and k_N at alpha and theta =60 degrees , 90 degrees and k_T=0, k_N=1. The effects of k_T and k_N cannot be neglected, especially at high alpha and theta . For the DISA Type 55P61 crossed-wire probe, the suitable values are k_T=0.30 and k_N=1.14. For the DISA Type 55P91 triple-wire probe, they are k_T=0.20 and k_N=1.01.