What are the two main types of magnetic particles used in Magnetic Particle Testing?

The primary distinction between the types of magnetic particles used in Magnetic Particle Testing is indeed between dry magnetic particles and wet magnetic particles.

Dry magnetic particles are typically used in powder form and are most effective in horizontal applications where the particles can freely settle on the surface of the test piece. They are often employed in environments where a more controlled application process is necessary, allowing for a less messy testing procedure.

On the other hand, wet magnetic particles are suspended in a liquid carrier, which can enhance the sensitivity and penetration of the particles into minute surface discontinuities. This suspension allows the particles to coat the surface of the tested material more thoroughly, increasing the likelihood of detecting flaws.

Both types have their respective applications depending on the specific requirements of the testing procedure, such as the type of discontinuities being detected, the geometry of the test piece, and the environmental conditions. Understanding these differences is essential for a Level 3 technician to choose the appropriate method and materials for effective magnetic particle testing.