Real process fluids such as emulsions and suspensions are optically absorbent as well as inhomogeneous. Using phase-Doppler anemometry (PDA) for investigating the spray cone, the inhomogeneities have led to incomprehensible size distributions. In this paper, solutions of instant coffee and condensed milk, representing typical process fluids, were chosen for PDA measurements in comparison with PDA applied to water droplets with the same atomization process in order to clarify the reasons for the measured broad size distributions. By applying PDA to monodisperse droplets and to ''monodisperse'' and real polydisperse sprays consisting of such fluids, it is shown how the measured size distributions arise. Based on this knowledge, the real size distributions are reconstructed and compared with that of water atomization. Therefore, PDA can in future also be applied to real process fluids, and process control, based on the information provided by PDA, is coming nearer.
