the detection pipe 231 the detection lens 232 may be built in the detection pipe 231 the detection lens 232 may be coupled with an inner surface of the detection pipe 231 and may adjust focus of the laser beam the detection filter 233 may be built in the detection pipe 231 the detection filter 233 may be coupled with the inner surface of the detection pipe 231 and may prevent heat damage by blocking infrared radiant heat coming from the pipe 50 in this case the detection lens 232 may be arranged adjacent to the pipe 50 and the detection filter 233 may be arranged adjacent to the detection connector 221 the detection plate 234 may be coupled with the detection pipe 231 and formed to protrude in a lateral direction the detection plate 234 may have a curvature corresponding to the outer surface so that the detection plate 234 is in contact with the pipe 50 the detection belt 235 may be formed to cover outer surfaces of the detection plate 234 and the pipe 50 the detection belt 235 may limit movement of the detection pipe 231 by fixing the detection plate 234 to be in close contact with the pipe 50 in this case since the detection pipe 231 moves along the circumferential surface of the pipe 50 a detection point of the pipe 50 may be varied a pipe damage detection method according to an exemplary embodiment of the present invention having the construction described above will be schematically described below fig4 is a schematic flowchart for describing a pipe damage detection method according to an.