The conductivity technique used provided a good degree of accuracy in ascertaining local variations of phase holdups. Results successfully determined the transition zone in heavy particle fluidized beds and showed a gradual variation of phase holdups in light particle systems. With light particle systems, the local particle-liquid heat transfer coefficient measurements revealed a gradual variation with axial distance at low liquid and gas velocities. Measurements at higher flowrates presented a flat constant profile. Consequently, interpretation was limited by the precision of the readings thus necessitating technical enhancements (probe design, current supply value, probe protection layer). With heavy particle fluidized beds, the particle-liquid heat transfer coefficient was constant in the dense bed region and decreased in the transition zone at high flowrates. At low liquid or gas velocities, h(ls) remained constant in both the dense bed and disengagement zones. Results in both cases were correlated with the variations of local phase holdups.