Method for determining the relative amount of deformation induced in a sealing component by a sealing

A nondestructive method for determining the amount of deformation induced in a material by a compressive force is provided that includes the steps of uniformly dispersing a quantity of a particulate tagging substance in the material whose presence and distribution is detectable by a form of radiant energy, applying a compressive to the material, and then determining the extent to which the material is compressively deformed by transmitting the appropriate radiant energy through the material to determine changes in the density and distribution of the particulate tagging substance. The method may advantageously be applied to determine the extent to which a granular material such as asphalt concrete has been compacted over a roadbed, as well as to determine strain and wear patterns in gaskets formed from elastic materials.