The Application Status of Electronic Speckle Pattern Interferometric Nondestructive Testing

Based on modern high technologies such as laser, video, electronics, image processing and holography, ESPI(Electronic Speckle Pattern Interferometry) is a non-contact measuring method, which can measure the small static and dynamitic surface deformations and reveal flaws by looking for flaw-induced deformation anomalies. With the advantages of high precision, high sensitivity, wide frequency bandwidth and full-field real-time testing, it has a promising future in engineering. Its basic theory and recent applications in nondestructive testing are reviewed. Finally, its scope for improvement is discussed.