Patent ID: 6477473
Filing Date: 2002-11-05
Classification: G01L,G01N

Abstract:
A method for measuring the internal stress in a material comprising the steps of:(a) applying a transducer probe in physical contact with the material; (b) applying at least one receiving probe in physical contact with the material; (c) applying a contact force at an interface between said probes and the material, comprising the steps of placing a variable force ram in physical contact with said probes, attaching a load frame to said variable force ram, and securing said load frame to the material; (d) transmitting a critically refracted longitudinal wave through the material from the transducer probe to the at least one receiving probe; and (e) calculating the internal stress of the material as a function of a travel time from the transducer probe to the at least one receiving probe of the longitudinal wave through the material.