What is the purpose of agitation during the immersion method?

• A. To continuously expose fresh penetrant and break apart penetrant into smaller easier-to-remove drops
• B. To heat the penetrant
• C. To increase penetration depth by pressure
• D. To dry the surface quickly

Answer: (A)

Agitation during immersion keeps fresh penetrant in contact with the surface and helps break up the liquid so it can flow into small features and be carried away as needed. This mechanical action reduces air entrapment on the surface and within discontinuities, ensuring penetrant continuously wets and penetrates defects rather than stagnating. It’s not about heating, applying pressure, or drying the surface—those effects come from other steps or conditions, while agitation’s job here is to refresh the penetrant film and promote penetration by preventing air pockets and by promoting penetrant flow.