Defect Location Detection Technology In The X-ray Digital Imaging Research

Radiography testing is one of the important methods in NDT and locating position of defects is a critical part in radiography. The methods of location defects include: Density Method, Stereo-scope Observing , Industrial CT and Parallax. Compared with other methods, parallax is widely applied for its convenience and strong applicability. Parallax is also limited under some circumstances because of the low precision. We analysis the factor has effect on the precision of locating in parallax. On basis of that, we present method to correct the parameters in parallax and to realize parallax by rolling the workpiece instead of moving workpiece. This is confirmed to be effective by experiments.When problem of locating depth of defects is well settled, we establish the three-dimensional model of defect to calculate the three-dimensional coordinate of defect. The model has been proved to be correct by experimental data.