the pipe from a position of the device that can only be controlled in its longitudinal position the camera will preferably be equipped with autofocus system the camera pointing angle will be in a relation to the two directions upper lower and right left and the movements will stay within the inside of the glass dome this arrangement guaranties the water tightness of the system and may be realized with parts resembling surveillance cameras and anti vandal glass domes according to a fourth characteristic the device includes a fix or even swivelling camera at the bottom 3 the camera is protected by a flat port hole depending on its distance to the bottom of the pipe and the water clarity this camera shows the lower immersed part of the pipe observation is possible up to the agitated and turbid zone located between the flowing liquid zone and the pipe the camera can also visualize the projection of the light beams 6 to the bottom surface as used in sixth characteristic for measuring the distance according to a fifth characteristic the device in includes a lighting system that can be built in with the cameras with night vision or can be independent with white or infra red spotlights preacuations will be taken to avoid light reflection on the.