1. A method for detecting an operational condition of a tray of a distillation column, comprising: providing within a tray of a distillation column a sensing cable including an optical fiber sensor array, the optical fiber sensor array operatively coupled to an optical signal interrogator; monitoring with the optical signal interrogator an output of the sensing cable corresponding to at least one sensor location on the optical fiber sensor array; classifying the output of the sensing cable as one of a predetermined set of classifications including at least a stable condition classification and a unstable condition classification determined based upon the output relative to a predetermined threshold; and generating a signal when the output of the sensing cable is classified as the unstable condition classification.