缺陷与投影的对应关系 V型及U型剖口的坡面未熔合缺陷在底片上的投影和缺陷的实际位置存在一定的几何对应关系,因此,由缺陷在底片上的位置可以推知缺陷在焊缝中的深度,其具体方法如下。如图1所示,S:点源,SO:焦距f,壁厚GH为t,F是缺陷实际位置,A是F在胶片上的投影,GN Defects and projection of the corresponding V-shaped and U-shaped section of the slope unmelted defects Projection on the film and the actual position of the defect there is a certain geometric correspondence, therefore, by the position of the defect in the film can infer defects in the welding The depth of the seam, the specific methods are as follows. Shown in Figure 1, S: point source, SO: focal length f, thickness GH is t, F is the actual position of the defect, A is the projection of F on the film, GN