Adhesive Tape

Electronic Speckle Pattern interferometry (ESPI) is a non-destructive optical method for studying surface deformations. It relies on the interference between diffusely reflected light from the test object and a reference beam.This is one of the most sensitive interferometric technique, so that we can measure sub-micron level displacements either in plane or out of plane. The images before and after deformation are recorded by a CCD camera and analysed using an image analysis software. Deformation causes variations in the fringe pattern.These variations can be analized with the help of the software provided to find the deformations.