A new method of frequency response analysis of an adsorber, with modulation of the adsorbate molar supply instead of traditional modulation of the reservoir volume, is presented. A semi-batch mode of operation is considered, for three different types of mass transfer mechanisms inside the particle : Langmuir kinetics, micropore diffusion and parallel pore and surface diffusion. Frequency responses to four different modes of perturbation are investigated : sinusoidal, square wave, triangular wave and saw-tooth wave. Except for the sinusoidal input modulation, the system pressure response contains higher harmonics, which makes the study of fast dynamics more feasible by using relatively low frequencies of the input perturbations and analyzing the higher harmonics in the output signal.