Tuesday, August 25, 2015
RFT Technology Described
PICA’s pipeline inspection tools consist of flexible in-line tools that employ Remote Field Technology (RFT) for measuring pipe wall thickness. RFT technology works by detecting changes in an AC electromagnetic field generated by the tool. As the field passes through the pipe wall it is attenuated and delayed (it becomes stronger in areas of metal loss and the time delay is less). The field interactions are measured by on board detectors, and subsequently processed on the tool itself using A/D converters and DSPs. The processed data is either stored onboard, or sent to the above-ground world over a multi-conductor wire-line for storage on a laptop. Once all the data is acquired, sophisticated analysis software is applied to generate accurate information on the wall thickness of the line. Figure 1 (below) schematically shows the magnetic coupling path between the exciter section of the tool and the detector array.
