Magnetostrictive materials have been successfully used for the manufacture of various sensors. S-transformation is proposed for evaluation of the characteristics of the signals and tuning of the sensors by considering the requirements of the considered application. The proposed method was used to evaluate the response of a Terfenol-D rod to impulses. The signals of a coil and magnetic head were compared to the velocity signal of a laser vibrometer. The study indicated that s-transformation allows the evaluation of the frequency response characteristics and its variation with time. Magnetic field variation of the Terfenol-D could be effectively used with a coil to monitor the volumetric changes which is directly correlated with surface velocity, and first derivative of an external force. Very compact switches could be designed based on the magnetic head design.