Video and laser-based measurement

Paul Boughton
Pipe measurement specialist Optical Metrology Services (OMS) Ltd is providing video and laser-based measurement services to several UK-based building, construction and utility management companies. These services include the inspection and measurement of underground pipes, including gas, water and rainwater drainage pipes on UK motorway networks. These include measuring the geometrical features of pipes such as the ovality.

Many of the UK’s motorway networks have holding pods installed underneath the road surface, which are designed to control the drainage of water from the road surface in order to prevent flooding. These pods are typically positioned 5m underground, either on the hard shoulder or on the grass verge at the side of the motorway. The pods comprise tightly-packed sheets of plastic, around 3 metres square, with a 500mm diameter plastic pipe running through the pod. The pipes, which are typically between 3m and 36m in length, have small slits along their length, which allow water to slowly soak through to the pod.

Typically, a motorway will require multiple pods at critical flood prevention areas. After installing these pods, it is sometimes necessary for the installer to determine the exact shape of the pipes in order to demonstrate that they meet their own specification requirements.

Using its unique video and laser-based measurement tools, OMS engineers are able to measure these pipes in situ, in order to verify their roundness and to look for signs of damage or blockage inside the pipe.

Kevin Darnell, Project Manager at OMS Ltd commented: "Typically, the customer will ask us to measure the inside diameter of installed pipes, which we do by laser measuring at several points along the pipe’s length using our Pipe CheckerÔ tool. At a later point in time, we would then return to those pipes in order to measure the same parameters again. From our measurement results, we can then see whether a pipe has changed shape over that period. The same tool used for laser-based measurements is also equipped with advanced video inspection capability, including the latest pan and tilt camera technology and auto-focus zoom lenses, tractor systems and motorised cable reels. By moving the tool through the entire length of a pipe, we can visually identify whether there are any areas of concern within the pipes."

OMS’ Pipe Checker tool is ideal for inspecting the inside of pipelines and other structures such as manifolds. With both video and laser-based measurement capabilities in a single tool, only two OMS engineers are required on site to inspect each pipe. OMS engineers are trained to work in confined spaces.

The Pipe Checker tool is capable of measuring pipe diameters from 300mm up to 1,000mm. Larger wheels can be fitted to the tool’s motorised tractor unit if the tool needs to move through sludge inside the pipes.

As Kevin Darnell states: "The measurement data we collect from the PipeChecker tool provides customers with a traceable method of identifying whether a pipe is blocked, changing shape over time, incorrectly installed, or whether it is out of its manufacturing specification."

For more information, viist

Recent Issues