Non-Destructive Examination (NDE)
Definition
Inspection methods that do not alter or consume the evidence: visual inspection, photography, dimensional measurement, dye-penetrant testing, ultrasonic testing, and radiography. NDE is performed before any destructive sampling.
- Examples
- Dye-penetrant, ultrasonic testing, radiography
- Field
- Engineering failure investigation
- Timing
- Always before destructive sampling
Common questions
Why is NDE performed before destructive sampling in a failure investigation?+
Cutting, sectioning or removing material for lab analysis is irreversible, so surface and volumetric NDE methods map the extent and location of defects first, ensuring destructive sampling targets the right region without losing information the intact part could have provided.
What is the difference between dye-penetrant and radiographic NDE?+
Dye-penetrant testing only reveals defects open to the surface, such as surface cracks, while radiography can detect internal flaws like voids or inclusions beneath the surface that dye penetrant cannot reach.
Related terms
- ASTM E860
- Standard Practice for Examining and Preparing Items That Are or May Become Involved in Criminal or Civil Litigation. Specifies documentation requirements and...
- Destructive Examination
- Testing that consumes or modifies the evidence: sectioning for metallurgical mounts, chemical digestion for composition analysis, mechanical testing to failure. Requires notice...
- Evidence Preservation
- The discipline of maintaining physical evidence in its post-incident condition until all parties have had the opportunity to examine it. Includes both...
- Hypothesis Generation and Testing
- The step in failure analysis where possible causes are listed systematically, then each is tested against the physical evidence and engineering calculations....
- Root Cause
- The fundamental, underlying deficiency from which the failure originated. Distinguished from immediate cause (the final physical event) and contributing factors. Root-cause analysis...