What is a typical example of a "nonrelevant indication" in penetrant testing?

In penetrant testing, a "nonrelevant indication" pertains to signals or indications that do not signify actual defects in the material being tested but arise from other factors related to the part's characteristics. Indications due to part geometry or design configurations are classic examples of this, as they reflect the physical shape and structural aspects of the component rather than any materials failure, discontinuity, or flaw.

For instance, if the shape of a part creates shadows or outlines that are interpreted as indications during the penetrant testing process, these are simply a result of the geometry rather than actual defects in the material. Thus, recognizing these nonrelevant indications is vital for effectively interpreting test results and ensuring that only true defects are addressed during inspections.

In contrast, other types of indications mentioned could stem from actual issues: surface contamination and coating errors could potentially lead to false indications, while material fatigue might indicate genuine problems in the integrity of the material. Understanding the distinction between relevant and nonrelevant indications helps in the accurate assessment of the material's condition during penetrant testing.