In the development process, which statement is true?

• A. Developers aid in the extraction of entrapped penetrant.
• B. They remove the penetrant completely.
• C. They are optional.
• D. They replace the need for penetrant.

Answer: (A)

In liquid penetrant testing, development uses a developer to draw penetrant that is trapped in flaws up to the surface so that an indication becomes visible. The developer’s capillary action concentrates the residual penetrant at the surface, creating a contrasting line or spot under the inspection light, which helps locate and characterize defects. It doesn’t remove all penetrant by itself, and it isn’t optional or a replacement for penetrant—the development step follows penetrant application and removal, and it is essential for clearly revealing flaws.