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 having at least one sensor location, the optical fiber sensor array operatively coupled to an optical signal interrogator, wherein one of the at least one sensor location being located in the distillation column in the vicinity of a tray; 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.