This paper reports on the experimental investigation carried out to evaluate the interfacial area of contact to characterize a variable-area multistage bubble column (with contraction and expansion disks), which has been conceived, designed, and fabricated as a wet scrubber for control of air pollution; in addition, it has versatile use as a gas-liquid contactor in chemical process industries. Correlations developed for predicting the interfacial area of contact in terms of fractional dispersed-phase holdup have been found to be encouraging and highly significant from statistical analysis.