Magnetic Flux InspectionThis equipment uses very powerful rare earth magnets in order to near saturate the plate in the area of the scanning head. Coil sensors placed between the poles of the magnetic bridge detect the flux leakage fields and provide a low voltage output signal to the electronic module for processing and real time display. The electronic processing and display module is common to both of the MFE Scanning Systems.
Proper use of this equipment does not require the setting of calibration thresholds as the amplitude of the signal is an unreliable indicator of remaining wall thickness. Since MFL is a quantitative inspection procedure, no calibration can be made to meet all configurations of defects possible. The functioning plate shall have the ability to determine that all sensors are functioning. The functioning plate must be able to have the ability to represent both through holes and soil side corrosion. Since the plate is used only for instrument functioning, the functioning plate used for a coated tank bottom may be a bare plate or a nonferrous material may be placed on top of the plate to simulate coating.
The achievable sensitivity of any Flux Leakage Inspection on any given floor is directly dependent on the overall top surface condition. In ideal conditions it is possible to find very small corrosion areas on the underside of the plate.
Magnetic Flux Leakage - The equipment utilized for the Flux Leakage Inspection of Tank Floors By Nova Data Testing is the MFE 2412/1212 Scanning System or the Silverwing MLF 2000 Tank Floor Scanner.