Which two forms of indicating mediums are used in magnetic particle inspection?

Which two forms of indicating mediums are used in magnetic particle inspection?

• A. Wet and dry process materials
• B. Wet and dry process materials
• C. Iron and ferric oxides
• D. High retentivity low permeability

Answer: (A)

Magnetic particle inspection uses indicating media in two formats: wet process and dry process. In the wet method, fine iron oxide particles are suspended in a liquid (oil or water) and applied to the surface; in the dry method, a fine ferromagnetic powder is dusted on as a dry material. When the part is magnetized, any flux leakage at a defect draws the particles to the area, creating a visible indication. The other options describe either the material makeup of the particles (iron and ferric oxides) or a magnetic-property characteristic (retentivity and permeability), not the format of the indicating medium.

Magnetic particle inspection uses indicating media in two formats: wet process and dry process. In the wet method, fine iron oxide particles are suspended in a liquid (oil or water) and applied to the surface; in the dry method, a fine ferromagnetic powder is dusted on as a dry material. When the part is magnetized, any flux leakage at a defect draws the particles to the area, creating a visible indication. The other options describe either the material makeup of the particles (iron and ferric oxides) or a magnetic-property characteristic (retentivity and permeability), not the format of the indicating medium.