EN
We have measured magnetic response of second-generation high temperature superconductor YBa_2Cu_3O_{x} wire and Nb thin film in perpendicular ac field as a function of temperature. We compare experimental complex ac susceptibility to the calculated susceptibility based on the model of Bean's critical-state response in two-dimensional disk in perpendicular field. The harmonic analysis is needed for comparison between the model and the experimental data. We present a method of linking model and experimental susceptibility. Good agreement of experimental susceptibility with model susceptibility of 2D disk allows contactless estimation of critical depinning current density and its temperature dependence.