Remote Field (RFT)

RFT is also a suitable technique for detection and sizing of localized defects such as pitting. The analysis is performed in standard XY vector plane. Pit depth is evaluated with a depth curve such as used in eddy current. Detection and sizing of flaws in the vicinity of support plates may be improved by using a dual-driver probe and a dual –frequency analysis procedure.

Furthermore, the voltage plane permits discrimination against non relevant indications. The TCS 5700 performs real time voltage plane probe balancing, data acquisition, and data display.

TCS 5700

*Dual –frequency RFT capability with real-time mixes
*4 RFT coil inputs
(up to 8 with expanded RFT option)
Current or voltage drive, adjustable
*Low frequency range starts at 20 Hz
*Adjustable bandwidth from 8 Hz to 200 Hz
*Phase-to –depth and voltage-to depth curves for wall loss measurement
*Voltage plane or vector display.

Magnetic Flux Leakage (MFL)

MFL is based on the magnetization of the material to inspect using a strong magnet located inside the probe. As the probe encounters a wall reduction or a sharp discontinuity, the flux distribution varies around that area and is detected either with a Hall -effect transducer or an inductive pickup coil.

MFL is suitable for wall loss measurement and detection of sharp defects such as pitting and grooving .MFL is effective for aluminum finned carbon steel tubes because the flux leakage filed is mostly unaffected by the presence of such fins.

IRIS

IRIS is an ultrasonic technique well suited for petrochemical and BOP tube inspections. The technique uses an ultrasonic beam to scan the tube ID surface in a helicoidal pattern ensuring that the tube full length is tested. The TC 5700 monitors the front wall and the back wall echoes in order to measure the tube wall thickness.

The TC 5700 display provides the analyst with extensive information for decision making. When a defective area is observed, the acquisition process can be suspended and analysis performed on a composite display .This display is made of a color C-scan and a B-scan with real-time animated cross sections a D-scan to show the profile of the tube.