Level 1 and Level 2 penetrants maintain what brightness percentage?

• A. 40%
• B. 50%
• C. 60%
• D. 70%

Answer: (B)

In fluorescent penetrant testing, the brightness level of indications is a key quality metric that ensures defects are visible but not overwhelmed by glare. Level 1 and Level 2 penetrants are designed to retain about half of their original brightness under inspection conditions. That 50% brightness provides a reliable, consistent contrast against the background and the developer, making indications easier to interpret across different components and inspection setups. If brightness were much lower, faint indications might be missed; if it were much higher, small defects could become harder to discern. Therefore, the standard target is 50% brightness.