Illinois Tool Works Inc.
VIDEO EXTENSOMETER SYSTEM WITH REFLECTIVE BACK SCREEN

Abstract:

The present disclosure describes systems and methods for conducting deformation (e.g., extension and/or strain) measurements based on characteristics of a test specimen using light sourced from a single side of a test specimen. The light source and an imaging device are arranged on a single side of the test specimen relative to a back screen while the light source illuminates both a front surface of the test specimen and the back screen. The back screen reflects light to create a silhouette of the test specimen. The imaging device captures images of one or more markers on a front surface of the test specimen, as well as measuring position of the markers during the testing process. The imaging device also measures relative changes in position of the edges of the test specimen during the testing process, by analyzing the edges of the silhouetted image created by the reflective back screen.