At least two operators pulled a mandrel though the pipe to find pipe deflection, deposits or debris. When the operators were unable to pull the mandrel through, the guide ropes were marked, the mandrel removed, guides measured and the mandrel reset. The process was long, tedious and often resulting in digging up pipes for small problems. Operators didn’t know, with any certainty, what the cause of the mandrel’s stopping was: deflection, cracks in the pipe, debris or build up or simply human error.
With the onset of cameras and profiling, a more accurate, less physical and a quicker method of measurement was born. Quite simply, laser pipe profiling is the use of lasers with camera equipment to accurately see and measure pipe deflection, cracks and joints.
Since contractors in the United States began using laser pipe profiling, many states have recognized its value. Pipe conditions can be checked fairly easily before projects are completed and on existing pipes. Individual states began to require new pipe under roads to be scanned before the roads are opened so that road collapse can be avoided in the future. Florida was the first with several other states, including Kentucky, following soon thereafter. With my company, my primary focus is in Kentucky, therefore I have had much of my business linked to the new requirements of pre-acceptance pipe profiling. I also perform laser pipe profiling and no-dig repair in the surrounding states, but have traveled to Michigan and California to complete profiling, assist new Rausch Electronics customers and profiling with point repair.
Pre-acceptance pipe profiling involves scanning and measuring new pipe (often, but not always) under roadways for proper inclination and deflection. Contractors might own their own laser profiling equipment or hire a subcontractor to complete a profile on the new pipe before laying asphalt. State authorities set the acceptable standards, contractors lay the pipe and laser pipe profilers check the work reporting back to both the contractors and state — it is a check-and-balance system that allows for greater integrity of the results and a safe, finished road.
Currently, there are two types of laser pipe profiling: direct measurement and laser light ring. With direct measurement, the camera and laser measure the pipe circumference giving a visual, which is automatically relayed back to the user with immediate results of the scan as the camera travels through the pipe. The camera, laser and software do the bulk of the work thereby reducing human error. Laser light ring requires human data entry before any measurements can be made. Direct measurement allows for greater integrity of results, as there is no place for user setup or can the operator adjust data received. Rausch Electronics direct measurement system elevates operator intervention of data, field calibrations, operator tampering or operator error. Laser light ring is only able to figure an average of what it scans. It can show deflection but not measurement, whereas direct measurement does both.
What is direct measurement? Direct measurement uses a highly sophisticated pipe camera fitted with laser diodes around the lens of the camera — one to the left and one to the right. Once the operator has placed the camera within the pipe, he or she is able to drive the camera measuring distance from the manhole, as well as the circumference of the pipe. The operator can visualize the inclination of the pipe (while the software and camera system measure it) and can see when the circumference changes to fit a customer’s given specifications (5, 7 ½ or 10 percent deflection). He or she can also see what causes the deflection: debris (Do they need to clean the pipe?), cracks (Is a repair needed?), previous repair issues (Are there complications?) or pipe compression.
The software can provide pinpoint accuracy so that point repairs can be made as necessary. Digging is limited to an exact area if required, but with the Quick Lock system of one-way ratcheting point repair (similar to a heart stint in humans), I can provide many customers with a no-dig solution. Through the use of direct measurement, a precise dimension of the pipe can be obtained so that the perfect point repair sleeve can be put into place, thereby negating the need for a costly dig and replacement repair. It is not always easy for a manual measurement of the pipe’s interior, (i.e. size pipe and/or position of the repair point) and the direct measurement allows just that. The camera operator does not have to re-calibrate or adjust data. There is no need for third-party review of reports to double check measurements either.
Laser Light Ring
What is laser light ring? Laser light ring is similar to direct measurement in that it uses a camera system with lasers. A fixed rod with a laser on the end is strapped to the front of the camera system. The laser projects a “ring” of light against the interior wall of the pipe within the view of the camera. The camera and software work together to measure averages of the pipe interior. The operator can again visualize what causes a deflection. The pipe measurements are input by the operator and the laser ring bases averages from the operator measurement. Cameras must be field calibrated and operators must enter data for the average measurements to be correct. Operators must choose lengths of rod specific to each job application to ensure that the laser projected will be in full view of the camera. A third party may be involved in reviewing and interpreting the data obtained from the laser profiling sessions.
For my business, I prefer the direct measurement equipment because I can measure for point repairs, cracks and joints and lacks external devices. Much of the work I do is pre-acceptance, which requires and quicker turnarounds. Therefore, direct measurement provides a faster report output for my customers who are working on project deadlines. Direct measurement is also important to me to get precise measurement for use with Quick-Lock point repair.
I certainly would not want to step backward to using mandrels now that I have found a proven product and method that far surpasses them. The 21 century of pipe profiling is clear. My pictures give my customers more than a thousand words: See the problem, see the solution.
Brian Gipson is owner of PipeCheck, based in Bowling Green, Ky.