Liquid penetrant testing is capable of detecting

Liquid penetrant testing is capable of detecting

• A. Internal delaminations not open to surface
• B. Discontinuities open to the surface
• C. Subsurface voids
• D. Cracks behind coatings

Answer: (B)

Liquid penetrant testing detects flaws that have an opening to the surface. The penetrant is applied and can enter only cracks or discontinuities that reach the surface, and after excess is removed and a developer is applied, the penetrant drawn to the surface reveals an indication that can be seen under proper lighting. Because of this surface-access requirement, defects entirely enclosed within the material, or ones that are beneath coatings with no surface opening, are not reliably detectable by this method. In practical terms, surface-breaking cracks and similar flaws show up, while internal delaminations, subsurface voids, or cracks behind coatings do not.

Liquid penetrant testing detects flaws that have an opening to the surface. The penetrant is applied and can enter only cracks or discontinuities that reach the surface, and after excess is removed and a developer is applied, the penetrant drawn to the surface reveals an indication that can be seen under proper lighting. Because of this surface-access requirement, defects entirely enclosed within the material, or ones that are beneath coatings with no surface opening, are not reliably detectable by this method. In practical terms, surface-breaking cracks and similar flaws show up, while internal delaminations, subsurface voids, or cracks behind coatings do not.