The study of fluidized beds dynamics is a complex task. Thus, different experimental techniques have been developed to evaluate the characteristics of fluidized beds, including pressure, capacitance, optical and/or heat transfer probes. In addition, imaging techniques have been used to observe the interior of the bed. Simons reviewed the use of radiation and capacitance imaging, and studies on the application of magnetic resonance imaging (MRI) for the determination of the time average particle velocity , time average voidage and/or the mean length of jets in perforated plate distributors have been conducted .