A PIPE-PROFILING ADAPTER FOR CCTV INSPECTION CAMERAS - DEVELOPMENT OFA PIPE-PROFILING INSTRUMENT

The principle of the optical section has been used to develop a profil ing attachment for CCTV pipe inspection cameras. A light source, place d in front of the camera, projects a ring of light onto the pipe wall, which is then viewed by the camera. Any distortion in the pipe wall w ill be made visible by the light ring. The CCTV image is digitized by an electronic frame grabber and the light ring image is located by spe cially developed pattern-matching software. The light ring shape is th en analysed mathematically using a radial descriptor, which allows any distortion to be represented in terms of a Fourier series. The device has been tested in the laboratory and in the field, and has been used to examine pipe degradation both in sewers and in water mains.