What is the primary reason for cleaning the surface before performing magnetic particle inspection?

Cleaning the surface before performing magnetic particle inspection is essential to prevent contamination of the magnetic particles. Contaminants such as dirt, grease, oil, or old paint can interfere with the magnetic field and the distribution of the magnetic particles. If the surface is not properly cleaned, these contaminants may block the particles from entering surface cracks or defects, leading to false negatives—where actual flaws are present but not detected due to obstructions on the surface.

Moreover, a clean surface allows the magnetic field to be properly established and ensures that the particles can effectively detect any discontinuities present. This process is crucial for providing accurate and reliable results during inspection. By maintaining a clean inspection area, the effectiveness of the magnetic particle inspection method is maximized, supporting the overall integrity and safety of the components being inspected.