Magnetic Particle Inspection

Magnetic particle inspection is used to find surface defects in ferromagnetic materials such as steel and iron. Magnetic particles, which may be dry or suspended in a liquid and colored or fluorescent, are dispersed over the material’s surface. A magnetic field is then induced in the material which produces flux lines which will be distorted by defects. Care must be taken in surface preparation as scratches and irregularities will also distort magnetic flux lines.