PROBLEM TO BE SOLVED: To provide an instrument for accurately and faithfully characterizing the surface of natural or artificial lawn or the like. SOLUTION: This instrument for characterizing the surface S of the natural lawn, an artificial lawn flooring or the like, from a biodynamic view point is constituted of a step wherein a weight 24 is dropped from a prescribed height h onto the surface S, wherein the kinetic energy in the dropping of the weight 24 is converted into strain energy of the surface S, and wherein the strain energy is given back to the weight 24 by the surface S to be returned/jumped upwardly, and a step, wherein at least one parameter among I-V for expressing giving-back processing of the strain energy to the weight 24 by the surface S is detected to be combined with the treading characteristics of the the surface S. COPYRIGHT: (C)2005,JPO&NCIPI
