Laser Profiling: An Introduction

By Author: Stuart Small
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Laser profiling is a modern technology that requires the use of a laser beam to scan the inside of a pipe and correctly determine its alignment, diameter, ovality and capacity. It’s not the particular type of data collected on a normal basis. Instead, laser profiling is typically conducted just one time before handing over the on pipe projects in which the contract explains the roundness of the entire installation.

Municipalities and contractors that want to use the technology need to understand how laser profiling is developing as more and more jurisdictions specify it.

Deadly accurate

A laser profiler is known as a CCTV camera inspection unit with a tiny laser probe that can be found mounted to the front of it. The laser displays a ring of light around the inside of the pipe, while the software processes the data that it receives after analyzing the ring. While a TV image helps to determine the exact dimensions of a pipe, the laser profiler will provide hard data and almost perfect results within a fraction of the percentage point. And while the position of a CCTV unit is usually determined ...
... by the length of cable leading into the pipe, the laser profiler can determine its own specific location within just a few inches. Laser profiling devices can be costly but prices are decreasing as technology becomes more of a common thing.

Key benefits

The main benefits of the laser-based profilometry technology include its unique ability to quickly generate quantitative, high-resolution pictures by using a non-contact sensor. It may also be combined with other known NDT methods including ultrasound and eddy current, subsurface and OD features, to detect and map ID. LP sensors are useful in detecting and accurately mapping features such as corrosion and deformation (denting), pitting, wear, erosion, and even scale build-up. They can also be used to create high resolution visual photos of features in place of CCD video probes or cameras.

In addition to benefiting from the LP technology it’s imperative to understand the limitations as well. Laser-based profiling sensors are unable to “see through” the part; which means they only map part of the surface. Therefore, subsurface additions including inclusions will be undetectable with LP sensors alone. Also the target surface should be clean and dry. Water droplets, grease and oil on tube surfaces will lower the quality of any of the LP results.

Sensitive to environment

The technology isn’t without some issues. Some of the units are very sensitive to moisture, different temperature variations, and even small deviations in the laser angles will give incorrect results. The technology will not work well in pipes that are partially filled with water. It provides you with information only on any dry areas of the pipe. A solution here includes the addition of a sonar device to record the information when below the waterline. The software allows the 2 readings to be integrated into one result.

Laser profiling technology is still in the developing stages. We will often see inspection units that have the ability to offer more capabilities including micrometry and laser scanning. However, as technology grows more complex we will see a compensating demand for simplifying how to operate these units. Contractors will require a tool that won’t require such a highly trained technician to do data analysis or number crunching. They desire something that can be utilized by using existing operators and trucks.

The high desire for laser profiling is expected to increase as government workers seek new ways to ensure that they will receive the value for each construction dollar spent. Also laser profiling equipment companies and pipe manufacturers will more than likely benefit from stricter standards are lobbying municipal and state governments to accept laser profiling.

Author About:

Stuart Small from Stevens Rowsell Sheet Metal Engineering writes about Laser profiling. For more information about Laser profiling visit www.stevensrowsell.com