Fluctuating solids concentrations in fluidized beds, measured by capacitance probes, provide local Eulerian information on the bed dynamics. The objective of this research was to determine if time-series analysis of such measurements can determine the operating locus for the fluidized bed on a generalized fluidization regime map. Using traditional statistical analysis together with deterministic chaos theory, it is shown that the density fluctuation measurements indeed can be related to the dimensionless gas velocity and mean particle size, thus enabling location of the operational state on regime maps. This result holds promise as a means for monitoring of fluidized reactors during actual operations.