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.