Relevant Indication — Definition & NDT Use
An indication detected by NDT that represents an actual defect in the material (as opposed to irrelevant indications from geometry, coatings, or instrument artifacts). Distinguishing relevant from irrelevant indications requires proper technique, reference standards, and operator experience. Standards define criteria for determining whether detected indications are relevant flaws requiring evaluation.
From the inspector's bench, Relevant Indication is run as a defined sequence: equipment verification on a known reference, scan setup against the procedure, scanning the part, and writing the indications into the report. Procedure writing, inspector qualification, and the reference block establish the chain that lets a remote engineer trust an indication called a kilometre away from the office.
Relevant Indication is selected when the failure mode the engineer cares about — surface crack, internal void, wall loss, lack of fusion — lines up with what the technique is physically capable of detecting.
The most expensive mistake with Relevant Indication is treating it as a yes/no test rather than a characterisation — an indication called without a sizing strategy forces a repair where a fitness-for-service review might have left the part in service.
What does "Relevant Indication" mean in NDT?
An indication detected by NDT that represents an actual defect in the material (as opposed to irrelevant indications from geometry, coatings, or instrument artifacts). Distinguishing relevant from irrelevant indications requires proper technique, reference standards, and operator experience
Which standards govern the use of Relevant Indication?
Relevant Indication is most often referenced under ASME Section V together with the relevant ASTM practice or the matching ISO standard for the method; the contract or purchase order will name the controlling document and edition for any specific job.
What other NDT concepts should I read alongside Relevant Indication?
The most directly related entries in this glossary are "indication", "defect", "irrelevant indication"; reading those together gives you the surrounding vocabulary used in inspection reports and procedures.