ASTM E 1571

 Hei Inspktører.

This week I was reviewing some information on cable inspection by MFL, I came across a very interesting document called ASTM E1571.

This covers information for the examination of rope wire by Electromagnetism, ML and MFL to detect flaws and / or changes in the cross-sectional area of ​​these materials in diameters up to 2.5 "mainly.

One of the techniques that most caught my attention was the so-called alternating field MFL where the alternating field MFL probe rotates at high speed around the longitudinally moved test material and scans its surface helically.

In this case the rotating probe "spot" scans only a small area of ​​the material surface at any one time, that is, during the test, it is focused on a very small part of the total surface.

Thus, even an extremely small material defect represents a significant disturbance with respect to this relatively small material surface. In this case elongated material defects are indicated over their entire length.

Within the general limitations of this document we first find that it is applicable only to ferromagnetic materials, that it is very difficult to detect failures in or near terminations of ferromagnetic steel cables and connections and that deterioration of a purely metallurgical nature (brittleness, fatigue, etc. .) may not be easily distinguishable.