A combination of non-intrusive methods is used for the measurement of hydrodynamic properties of gas phase polymerization reactors. The presented work builds on the findings presented in previous articles. Three different techniques are presented here. Time averaged X-ray computer assisted tomography, 3-D single and 2-D multiple radioactive particle tracking and X-ray digital fluoroscopy. All these methods are applied in simple air-polyethylene experiments in laboratory scale fluidized beds. Whenever possible, the volumes of experimental results are combined into simpler plots and compared to existing models in the literature.