The monograph presents a review of classical and a presentation of new methodologies of non-invasive (non-contact) flow measurement techniques of nultiphase media and a number of algorithms applicable in the field.\nThe discussed methods are mainly based on the statistical analysis of collected measurement data, e.g. from electrical tomography systems or systems based on the tracking of radioactive particles.\nThe work is very valuable and interesting, because it provides comprehensive knowledge on selected aspects of process tomography. It is therefore a valuable supplement to other monographs and studies on this subject.\nProf. Witold Byrski