It is of great importance that both individual components and complete engineer- ing assemblies and structures are free from damaging defects and other possible causes of premature failure. A whole series of inspection instruments and tech- niques has been evolved over the years and new methods are still being developed to assist in the process of assessing the integrity and reliability of parts and assemblies. Non-destructive testing and evaluation methods are widely used in industry for checking the quality of production, and also as part of routine inspec- tion and maintenance in service....