Continuous gas-solid processes are applied in many industries with particulate products, e.g. for granulation or coating. In this contribution, the residence time behavior in a continuously operated prismatic spouted bed was determined by applying an impulse of magnetizable tracer particles. Experiments were performed with the original configuration and with separation plates including mouse holes of varying size between the different chambers of the ProCell 25 apparatus. It is shown that the shape of the residence time distribution is influenced by the separation plates. In order to quantify the backmixing between the chambers, discontinuous experiments were performed, and the bed mass distribution and the distribution of the tracer were measured and compared to the initial conditions.