What role does humidity play in the context of MPI?

Humidity has a significant impact on the behavior of magnetic particles during the Magnetic Particle Inspection (MPI) process, making the understanding of this factor crucial for accurate testing. When humidity levels are high, it can lead to the formation of a film of moisture on the surface of the test material. This moisture can disrupt the adhesion and distribution of the magnetic particles, causing them to clump together or not adhere properly to the surface.

Such disruptions can affect the ability of the particles to gather at the defect sites, which is essential for detecting discontinuities. If the particles are not properly distributed or are overly concentrated, it may lead to either false indications or undetected flaws, significantly compromising the integrity of the inspection results.

Thus, recognizing that humidity can interrupt particle behavior and influence the outcome of the inspection is paramount for MPI operators to ensure reliable results. This emphasizes the importance of controlling environmental conditions during the inspection process to achieve the best performance from the magnetic particles being used.