Time of Flight Diffraction (ToFD)
Dye Penetrant Testing involves applying a liquid penetrant to the surface of a material. The penetrant seeps into surface-breaking defects, and after excess penetrant is removed, a developer is applied to make the defects visible. LPT is particularly effective for detecting small cracks, porosity, and other surface discontinuities.
Advantages
• Portable (on-site and in-house).
• Relatively simple method.
• Sensitive.
What defects/indications can it detect?
• Surface breaking defects.
• Toe cracks.
• Surface porosity.
• Crater cracks.
Limitations
• Uses a flammable liquid.
• Power may be needed.
• Temperature dependent.
• A clean surface is required before inspection.
Alternative inspection methods
• Magnetic Particle Inspection (MPI) Note: Only on ferromagnetic materials.
• Eddy Current Inspection (EC).