Asme Section V Article 9 ((better)) -

: Looking directly at the surface, often within 24 inches and at an angle no less than 30 degrees.

| Nonconformance | Why It’s a Problem | |----------------|--------------------| | No light meter reading recorded | Cannot prove 100 fc minimum | | Viewing distance >24 inches without optical aid | Misses small discontinuities | | Annual eye exam missing for examiner | Invalidates examiner qualification | | Using acceptance criteria from wrong code edition | Reject/accept decisions invalid | | Remote visual without resolution chart | No guarantee of detectable flaw size | asme section v article 9

If you are looking for acceptance criteria for a pressure vessel weld, do not look in Article 9. Article 9 will tell you how bright your light must be (100 foot-candles minimum) and how long you must stare (retinal persistence), but it will not tell you if a crack is allowed. For that, you must refer to the referencing Code Section (e.g., ASME Section VIII, Div. 1, Table UW-35). : Looking directly at the surface, often within