FIBERSCOPE AND APPLICATION METHOD THEREOF

PURPOSE:To surely observe the contact state of a fuel rod pipe with the elastic projecting holding piece of a grid for holding the pipe by setting the direction of the visual field center line of an image guide so that it may form a minute angle such as 5-20 deg. with a plane including the respective axial centers of the image guide and a light guide. CONSTITUTION:The direction of the visual field center line of the image guide 2 of a side-viewing type fiberscope where a tip probe in a band shape and a staircase shape is formed is so set that it may form the minute angle such as 5-20 with the plane including the respective axial centers of the image guide 2 and the light guide 3 of the tip probe 20. Since the direction of the visual field center line of the image guide 2 is not in parallel with the plane including the respective axial centers of the image guide 2 and the light guide 3 of the tip probe 20 but forms the minute angle alpha therewith, an observation part by the image guide 2 is deviated with respect to the plane. Thus, the contact state of the fuel rod pipe with the elastic projecting holding piece of the grid for holding the pipe, for example, is surely recognized.