There is no doubt today that thermal and thermocapillary convection play a dominant role in momentum, heat, and mass transfer in the Czochralski crystal growth method. Because of the complexity of the problems, measurements in one point of the volume are not sufficient to illuminate the flow topography or to compare the experimental results with real or numerically simulated data. Therefore, it is of great interest to measure the temperatures and velocities in the whole field in order to qualitatively analyze thermally driven convection. The new experimental particle image thermometry method, based on computer-aided color analysis of the TLCs reported here, enables the simultaneous determination of the temperature and velocity fields.