Abstract: This paper aims to measure pulsed amplitude and pulsed frequency online for 30%TRPOkerosene solution/the HNO₃ solution through 38, 50 and 100 mm diameter discs and doughnuts pulsed extraction column by air purge method. It is shown that pulsed frequency and pulsed amplitude can be respectively determined by the instantaneous pressure drop and by the area of the instantaneous pressure drop within one period. The value of the area is direct proportional to the number of baffler and the parameter of free area ratio, but it increases exponentially with the diameter of the column and the pulsed amplitude. Based on above results, the correlation of the area and pulsed amplitude is achieved and then proved by experiments.