Magnetic Particle Inspection Level 1 Practice Exam

Which type of magnetizing medium produces the most pronounced indications?

1. A dry powder medium

2. A wet fluorescent medium

3. A solid medium

4. A gas-based medium

The correct answer is: A wet fluorescent medium

The wet fluorescent medium is particularly effective for producing pronounced indications during Magnetic Particle Inspection (MPI) due to its unique properties. This medium contains finely suspended magnetic particles in a liquid carrier along with fluorescent additives. When a magnetic field is applied, these particles align with the magnetic field and gather at surface and near-surface discontinuities, such as cracks or voids. The wet fluorescent medium not only enhances the visibility of the indications but also allows for better penetration into small defects due to its liquid form. The fluorescent aspect, activated by ultraviolet (UV) light, makes the indications glow brightly, thereby providing a clear contrast against the inspection surface. This increased visibility is critical for detecting subtle flaws that might not be as easily seen with other mediums, such as dry powder. In contrast, while other mediums can be effective to varying degrees, they generally do not offer the same level of clarity and sensitivity as wet fluorescent media. For instance, dry powder mediums may have limitations in their ability to cover small cracks or defects due to their solid and granular nature. Solid mediums are typically not used in effective MPI practice for this reason. Gas-based mediums are not employed in magnetic particle testing, as they do not provide the necessary magnetic properties needed for this method. Thus, the