What is the effect of varying particle density in MPI?

Varying particle density in Magnetic Particle Inspection (MPI) plays a critical role in the effectiveness of the inspection process. When the density of the magnetic particles is adjusted, it has a direct impact on how well the particles adhere to the surface of the material being inspected. Higher density particles tend to provide better visibility and clarity of indications because they generate a more pronounced magnetic field and increase the amount of magnetic flux that is concentrated at any surface discontinuities or defects. This enhanced adherence helps to create sharp, clear indications that are easily interpreted by the inspector.

In contrast, if the particle density is too low, the indications may be faint or less distinct, making it harder for inspectors to identify critical defects. Therefore, having the correct particle density is essential for accurate and effective inspections, ensuring that all relevant surface flaws are detected clearly. Adjusting particle density is an important consideration for achieving optimal MPI results.