Relevant Indication
A relevant indication is an NDT response produced by an actual material discontinuity that must be evaluated against the applicable acceptance criteria for accept/reject disposition.
Definition
Only relevant indications are subject to code acceptance criteria. ASME Section V/VIII, AWS D1.1, and API standards each define minimum reportable sizes and reject criteria for various flaw types.
Related terms
- Indication — An indication is the response observed during an NDT examination that requires interpretation to determine whether it represents a relevant defect, a non-relevant geometric effect, or a false signal.
- False Indication — A false indication is an NDT response not caused by an actual material discontinuity, instead produced by contamination, technique error, magnetic writing, or instrument artifacts.
- Crack — A crack is a linear discontinuity in a material with negligible opening width, resulting from stress, fabrication, or in-service damage, and is the most safety-critical defect type in pressure equipment and structures.
More data terms
A-Scan · B-Scan · C-Scan · D-Scan · S-Scan · L-Scan · Distance-Amplitude Correction · Distance-Gain-Size · Time-Corrected Gain · Gating
Where this comes up in practice
Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.
Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.