Method to measure deformation or vibration using electronic speckle pattern interferometry

摘要

The method involve illuminating the test item (1) with diffused coherent wave fields (2,3). These are produced by splitting (4) an unexpanded almost parallel or slightly convergent laser beam (5). The diffusers may be made of translucent material (6) or reflecting material (7). A video camera and image processing unit (8) monitors the behavior of the test item using a phase step or speckle correlation method. An Independent claim is included for an arrangement for measuring deformation or vibration.