Pipe profile gauged to precision

A laser profiler, originally developed for, and subsequently successfully proven in, the offshore oil and water/waste industries, is now being offered to general industry. The profiler offers a raft of advantages for the inspection and analysis of internal profiles in a number of varying and diverse applications. According to the Optical Metrology Centre, the company which has developed the product, it can be used to measure a number of different shapes such as rectangular ducting and moulds not just its original intended host – piping. The profiler, which can measure pipes from 150 to 500mm in diameter, uses a spinning laser to take more than 1,000 measurements every five seconds through a full 360°, with a typical profile comprising of 500 to 2,000 measurements. It can identify characteristics such as ovality, cracks, cavitation, wear, corrosion, overbending of plastic pipes and the resultant internal deformations and can even be used, in comparison mode, to measure profile changes over a period of time. One other primary area of use is for monitoring pipe work and ducting with maintenance schedules in mind. In this role it can be used to determine when something needs relining or modifying. The system uses optical triangulation to measure points on the surface being scanned. Variations in the surfaces colour can be compensated for by the software and the accuracy can exceed 0.2mm. The system also uses an inclinometer for use with vertical profiles to ensure that the profile is always oriented in the same way, regardless of the position of the instrument. It has been tested with a variety of pipe materials including steel, plastic, clay and cast iron as well as in concrete cavities, epoxy coated structures and ductings. The module itself is made from anodised aluminium, it has a scratch resistant sapphire window, uses lemo connectors and is ruggedised making it suitable for general use. The system comes with either Windows software or a Software Development Kit version using National Instruments' Labview that will allow the user to integrate this system into their own applications. The basic software allows the user to perform least squares circle fits and automatically computes ovality measures where appropriate. The resulting information is automatically stored to disk in a sequential manner allowing rapid inspection of pipes or other structures. The inventor of the profiler, Dr Tim Clarke told Eureka: "We know that many companies need this type of measurement. The profiler can be adapted to meet the needs of any industry needing fast, accurate information about internal structures. We are expecting that this tool will be of interest to users in the process and nuclear industries as well as those in production engineering. An accurate profile can be the key to quality control." Optical Metrology Centre Design Pointers The profiler can take 1,000 measurements every five seconds It can identify a number of internal features such as ovality, corrosion, wear and can be used to compare profiles from previous measurements It is not restricted to round profiles as it can be used for ducting an moulds