Asme Section V Article 9 !link! Online

Measured density or grey level shall meet T‑954 requirements over the area of interest.

Using tools like borescopes, mirrors, or cameras when the area is hard to reach. Translucent Visual Examination: asme section v article 9

This is the most critical factor. The minimum light intensity required at the work surface is 100 foot-candles (1076 lux). Measured density or grey level shall meet T‑954