10. Conclusion

After briefly recalling the nature, purpose and field of application of non-destructive testing, we began by reviewing the main principles of defect detection and the physical bases governing the processes and their performance. We then describe in greater detail the physical principles, design and implementation of the 6 main families of non-destructive testing processes: optical processes, penetrant testing, leakage flow processes, eddy current processes, radiographic and related processes, and ultrasonic testing processes. We have deliberately omitted leak testing procedures which, although traditionally included in the field of non-destructive testing, are essentially related to vacuum technology [47] . The same applies to acoustic emission techniques, which are the subject of a separate article, and infrared thermography...