In the context of fluorescent, post-emulsifiable penetrants, what should be determined by experimentation?

In the context of fluorescent, post-emulsifiable penetrants, determining the length of time for the emulsifier to remain on the part is crucial for effective testing. This time influences the development of the penetrant, allowing it to properly interact with the material's surface and ensuring that any flaws can be accurately detected afterwards.

The emulsifier's main role is to wash away excess penetrant that has not entered any defects, thereby preventing false indications during inspection. If the emulsifier is left on for too short a time, it may not effectively remove excess penetrant. Conversely, if left on for too long, it can wash away penetrant that has entered defects, leading to missed indications of flaws.

Experimentation helps establish the optimal duration based on the specific material and penetrant characteristics. Different materials may require different emulsifying times to achieve the best balance between removing excess penetrant and preserving penetrant within flaws.