EDF research program on circulating fluidized beds includes, besides mock-up studies and numerical codes development, on-site measurements at Emile Huchet 125 MWe power station (in Carling). This publication concerns the last results obtained on dynamic heat transfer measurements. A method to solve the inverse heat conduction problem in the furnace wall, allowing the computation of the dynamic heat transfer coefficient at the wall from temperature measurements in this wall, has been developed. The analysis of the results obtained yields new insights on the effect of gas-solid mixing near the walls on heat transfer mechanisms. In order to improve this analysis, local concentration measurements are needed. A system for particle concentration measurement, using an optical probe, a video camera and an image processing system, is currently under development and will be set up in the riser of Emile Huchet power station. (author). 16 refs., 11 figs.