What can result from improper surface preparation before MPI?

Improper surface preparation before magnetic particle inspection can lead to increased detection of false positives. This occurs because contaminants such as dirt, grease, rust, or paint on the surface can interfere with the magnetic field and the visibility of the magnetic particles. These contaminants may create indications that do not actually represent defects within the material being inspected. Consequently, inspectors might misinterpret these false indications as genuine flaws, resulting in an inaccurate assessment of the component's integrity.

Effective surface preparation is crucial in MPI because it ensures that the magnetic field penetrates the material appropriately and that the magnetic particles can accurately indicate any existing discontinuities. Proper cleaning and surface treatment eliminate these extraneous factors, allowing for a clearer view of actual defects and thus enhancing the reliability of the inspection results.