What is Non-Destructive Testing?
Non-destructive testing (NDT) refers to the examination of materials without functionally relevant damage. The topic is a methodological foundation for reliable CT data, because it directly affects detection limits, measurement capability and reproducibility.
Scientific background
The scientific basis is rooted in the physical interaction of X-ray radiation with matter and in the mathematical data processing of projections. Particularly relevant is the comparison between radiation-based, ultrasonic and electromagnetic methods. For technical decisions, these relationships must be understood as a quantifiable measurement chain.
Relevant key metrics
- Spatial resolution, contrast-to-noise ratio and measurement uncertainty are the central parameters.
- Systematic effects are controlled via calibration, reference standards and repeat measurements.
- Parameter changes must be evaluated for robustness and transferability to series production conditions.
Standards and thresholds
- Standards: ISO 9712:2021 (personnel qualification), ISO 15708-1:2024 to -4:2025 (CT) as well as ISO 17636-2:2022.
- Typical thresholds (in practice): Probability of Detection (POD) and false-call rates are defined per inspection task; critical defect types receive maximum detection priority.
- Validity: Conclusive power depends on defect type, inspected volume, operator qualification and method validation.
Application in industrial practice
- Design of valid scan parameters for defect and measurement tasks.
- Objective interpretation of CT findings in development and series production.
- Comparability of results across systems, batches and time points.
Sources and reference date
- ISO 9712:2021 (Qualification and certification of NDT personnel).
- ISO 15708-1:2024 to ISO 15708-4:2025.
- ISO 17636-2:2022.
- Reference date: February 2026.