Interpretation — Definition & NDT Use
The analysis and evaluation of NDT data to determine if indications represent acceptable or unacceptable conditions. Interpretation requires knowledge of material properties, applicable standards, acceptance criteria, and defect characteristics. Experienced NDT technicians compare indications to reference standards and apply engineering judgment. Proper interpretation separates relevant flaws from irrelevant artifacts and supports fitness-for-service decisions.
From the inspector's bench, Interpretation 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.
Interpretation 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 Interpretation 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 "Interpretation" mean in NDT?
The analysis and evaluation of NDT data to determine if indications represent acceptable or unacceptable conditions. Interpretation requires knowledge of material properties, applicable standards, acceptance criteria, and defect characteristics
Which standards govern the use of Interpretation?
Interpretation 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 Interpretation?
The most directly related entries in this glossary are "evaluation", "acceptance criteria", "relevant indication"; reading those together gives you the surrounding vocabulary used in inspection reports and procedures.