ATMFL automatic operated to externally scan and detect loss in wall-thickness of tubular/pipe. Various Scanning Heads for multiple size of tubular/pipe. ATMFL Scanning Tool uses powerful magnet to magnetize the tubular/pipe circumference while encircling the outer diameter. Arrays of MFL sensor then scan, detecting flux leakage that occurs at areas with corrosion and wall thickness l... http://graffintech.com/magnetic-flux-leakage-inspection.php