Phase-locked Laser Infrared Non-destructive Testing Technology Research And System Development

With the rapid development of modern industry, in many areas of industrial production and manufacturing on, Non-destructive testing becomes increasingly important role. In many cases, to ensure accurate detection of a plurality of the security aspects of industrial production. So, It can be said of today’s industrial non-destructive testing is already an indispensable part of.Infrared thermal wave nondestructive testing is a non-destructive testing techniques specimen. The principle is that when the specimen subjected to thermal excitation, the surface temperature changes will ensue, resulting in differences. Using professional infrared camera can be observed surface temperature changes specimen. If the specimen contains the internal defects, the surface temperature shown in place will follow the temperature distribution is affected. Which can detect the internal defects of the specimen, including the defect position, shape, size. This method does not require contact with the specimen to complete, easy to operate, will not damage the specimen, including aerospace modern industry and so has a large area using this technology methods.Phase-locked laser is an active infrared thermal imaging technology, using a single frequency periodic excitation laser heat source, and then through the fast Fourier transform of the original calculation process heat map. Thus extracted is changing test surface temperature of the phase information. Comparing the amplitude of the phase diagram as FIG defect defect can provide more information and phase information of the measured object to satisfy a certain relationship between the depth. Key lock-in technique is to detect the infrared frequency selected, the detection frequency corresponding to a different type of inspection depth. Small phase information is detected by the surface characteristics of the specimen and the impact of uneven heating. This article contains a theory of phase-locked technology, And the laser heating source applied to the lock-in technique which, Independently developed a phase-locked laser system and has been associated with the experimental data.