Which method enhances the detection capabilities of MPI?

Implementing a rotating magnetic field significantly enhances the detection capabilities of Magnetic Particle Inspection (MPI). This method allows for a more comprehensive examination of the test surface because it can reveal defects that may not be easily identified with a static magnetic field. A rotating magnetic field generates a varying magnetic axis, which means that magnetic particles can orient in different directions depending on the position and nature of surface discontinuities. This capability enables the particles to accumulate at defect sites more effectively, thus improving the visibility of defects and making them easier to detect.

Using multiple colors of particles can help differentiate between various indications but does not fundamentally enhance the detection mechanisms themselves. Adjusting the particle size can affect the sensitivity of the inspection but does not provide the same level of comprehensive coverage that a rotating field offers. Applying heat to the component is unrelated to the efficacy of MPI in detecting surface defects, as it does not influence the magnetic properties or the behavior of the magnetic particles in the inspection process.