Liquid filled cavity inspection by camera - has seal above objective for compressed air introduction to displace medium

摘要

Vertical cavities filled with liquid media such as wells or boreholes can be inspected by lowering a television and/or photo camera with a light source into them. The mounting for the camera objective is equipped with a seal which slides on the cavity walls and has a through pipe for the admission of a pressurised gas. This displaces a certain section of the liquid medium in the vicinity of the objective. This creates satisfactory vision even when the liquid medium is contaminated or not transparent by nature. The camera can be moved along for inspection continuously, the design keeping the liquid medium away from the camera.