Which factor does NOT influence the effectiveness of Magnetic Particle Inspection?

The effectiveness of Magnetic Particle Inspection (MPI) is influenced by various factors that can affect the visibility and detection of flaws in the material being inspected. Among these factors, the color of the inspection medium does not impact the effectiveness of the method in terms of its technical function.

The choice of inspection medium—whether fluorescent or non-fluorescent—can affect the visibility of indications under specific lighting conditions, but the inherent detection capability of the MPI process remains unchanged regardless of color. The primary concerns for effective MPI include characteristics like material thickness, which affects magnetic field penetration; surface finish, which can influence the formation and visibility of indications; and heat treatment, which may alter the material's magnetic properties and impact the inspection results. Consequently, while color may play a role in visual inspection, it is not a critical factor in determining the overall effectiveness of the magnetic particle inspection process itself.