Liquid Penetrant Testing Level 2 (PT-2) Practice Exam

Under which condition can a low-viscosity penetrant provide better performance?

1. In high humidity

2. In low-temperature environments

3. In deep surface cracks

4. In rough surface textures

The correct answer is: In deep surface cracks

A low-viscosity penetrant excels in situations involving deep surface cracks due to its ability to flow into tighter spaces easily. This capability allows it to penetrate deeper into the cracks compared to higher-viscosity penetrants, which may not be able to infiltrate as effectively. The lower viscosity reduces the surface tension of the penetrant, enabling it to spread and fill gaps more thoroughly, which enhances the likelihood of detecting defects located in deep or intricate areas. Other scenarios, such as high humidity or low temperatures, could impact the performance of the penetrant but do not specifically capitalize on the characteristics of low viscosity like deep surface cracks do. Additionally, while low-viscosity penetrants can adapt somewhat to rough surface textures, their advantage is most pronounced in situations requiring deeper penetration.