Methods for identifying flow regime transitions in a trickle bed with structured packing based on the response of conductimetric probes are proposed. Time series of conductance measurements, obtained with an array of eight probes flushed to the reactor wall, are analyzed using tools borrowed from the theory of non-linear dynamics and symbolic dynamics. For the same range of gas and liquid velocities, the local hydrodynamics is inspected within a channel of the structured packing in a non-intrusive manner with a set of conductimetric probes imprinted on one of the corrugated plastic sheets that conforms a packing element. The local hydrodynamics within the channel is explored to interpret the trends of characteristic numbers calculated from the time series measured at the wall. The gas–liquid pattern shows a slugging behavior within the channel that is reflected in the analysis of the flushed probes response.