Industrial Radiology: Theory and practice - R. Halmshaw - Google Books

https://books.google.de/books?id=wJqBSA1exqoC&pg=PA60#v=onepage

Industrial radiography is a well-established non-destructive testing (NDT) method in which the basic principles were established many years ago. However, during 1993-95 the European Standards Organisa tion (CEN) commenced drafting many new standards on NDT…