Tham khảo tài liệu 'the welding of aluminum & its alloys part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Weld defects and quality control 215 Health and safety considerations - large areas may need to be closed off during radiography or enclosures must be provided in which the radiography is carried out. Radiographers must also be monitored for exposure to radiation. Access is required to both sides of the component the source on one side the film on the other. There are problems in detecting planar defects and fine cracks if these are normal to the beam. There is a limitation on the thickness that can be radiographed and defects easily detected. Skilled and experienced radiographers are required. The depth and through thickness dimension of a defect is very difficult to determine. Appendix A British and ISO standards related to welding and aluminium Listed below are all of the European and ISO standards that are related to the properties composition and product forms of aluminium and its alloys. The list also includes design codes welding specifications procedure and welder approval specifications welding guides and health and safety specifications. The list is up to date at the time of writing - May 2002 - but it should not be regarded as a definitive up-to-date listing as specifications in particular the EN and ISO standards are being introduced on an on-going basis and the equivalent BS specifications withdrawn. 216 Table No. Std source Number Part Year Title Key Wholly or partially replaced by Withdrawn Obsolescent Replaces 1 British BS 499 1991 Welding terms and symbols 2 British BS 499 Part 1 1992 Welding brazing and thermal cutting glossary 3 British BS 499 Part 2 1980 Specification for symbols for welding 4 British BS 499 Part 2C 1992 Welding symbols BSEN 24063 BSEN 22553 5 British BS 499 Part 3 1992 Specification for symbols for welding BSEN 22553 6 British BS 638 Arc welding power sources equipment and accessories 7 British BS 638 Part 4 1996 Specifications for welding cables 8 British BS 638 Part 5 1988 Specifications for accessories BSEN 60974-12 9 .
