Abstract: An imperfect pulse injection stimulus-response technique and an on-line computer system are usedto improve the experimental and data processing technique in the study of axial mixing in the pulsed-sieve-plate extraction column.Comparison of different methods for parameter estimation proves that the“Least-squares fitting method in the time domain”is superior to the moment method and some weightedmoment methods.The uncertainty in parameter estimation is discussed.The effects of pulsation onthe axial mixing coefficient of single phase flow in the column are examined.