E'NDE III (1998) Defect Evaluation with Emphasis on Deterministic Methods
Sizing of 3-D Surface Cracks by Using Hall Element Probe
D. Minkov and T. Shoji
ABSTRACT
The finite size of a Hall element measuring leakage magnetic field in the vicinity of surface cracks m magnetic materials is taken into account when sizing such cracks. An analytical expression is derived for the dependence of the Hall voltage on the average value of the z-component of the intensity of the leakage field of a crack over the volume of the active region of the Hall element. An existing method for crack sizing is modified for the case when the magnetic field measurements are performed by a Hall element probe. Computations are performed for sizing of different surface cracks with complex cross-sections and unknown shapes. The computed results show that precise sizing of the investigated surface cracks can be achieved by using the modified method. It is confirmed that the finite size of the Hall element has to be taken into account for precise sizing of surface cracks.
Publication Source: Electromagnetic Non-Destructive Evaluation III, Proceedings of the 4th International Workshop on E'NDE, Paris, France, 1998. Pages: 283... Publisher:IOS Press - Amsterdam
