Technology used in professional surveying of drainage systems
The professional surveying of drainage systems requires the use of specialist equipment to get to problem areas quickly and with a minimum of disruption to the site.
The most commonly used equipment consists of a closed circuit television system that allows a camera or cameras to be fed into a drainage system to relay live and recordable pictures of the interior of the system’s components.
Using the latest digital camera technology it is possible to enter and survey pipes as small as 50mm in diameter and as large as the biggest culverts.
The cameras are ultimately connected to survey vehicles that can be as far as 500 metres away from the site being surveyed.
Once a survey site is reached and pipes entered, a DVD recording of the images can be produced to provide the client with a hard copy to view.
The ‘business end’ of any drainage inspection system will be the remote cameras. Cameras are available from various manufacturers with sizes ranging from 50mm. These cameras obviously need to be waterproof and to be able to withstand high pressures, such as 50psi. Cameras can pan and tilt to provide a complete view of the interior of the pipe being inspected.
Lighting the scene within the pipe is vital and cameras often carry their own lamps.
Cameras can be introduced to a pipe and moved to the desired inspection site by a system of push rods that will move the camera along the pipe. Cameras can be of the self-righting variety to compensate for the rods causing rotation. These pushrods are flexible and so can bend easily to tackle corners or bends in the pipes.
The progress of the camera through the pipe is recorded by the monitoring equipment that measures the distance the camera has travelled.
Another method of delivering the camera into the pipe for inspection is for it to be mounted on a remote controlled crawler. These can be used in pipes with a diameter of 150 to 2000 mm. Crawlers are typically powered by small electric motors up to 80v and a variety of accessories are available to assist in accessing various types of pipes.
Crawlers allow for a camera to be fitted to the front or mounted on top via an extending assembly.
Cameras are operated by remote control from stand alone units sometimes working in tandem with a PC.
In addition to cameras, sonar units can be used in the same way to allow liquid-filled pipes to be acoustically profiled. The actual scanning unit has a pressure balanced transducer at one end and pitch and roll sensors to identify the orientation of the unit. The scanner is connected to a laptop computer via an umbilical cord and appropriate software of course needs to be loaded for the computer to analyse the data. This method is useful in that it allows surveying of pipes without the need to drain them.
Express Drainage Surveys
Here at Express Drainage Surveys we offer investigative drain surveys using the latest CCTV equipment to ensure any problems are quickly identified. Our expert team are on hand to recommend any further action required and carry out any necessary repairs to restore full function to your drainage system.