scope:

Recommends validation grades and validation methods for the following two classes of arc welding power sources, equipment and accessories: a) equipment constructed, calibrated and used to the accuracy specified in BS 638: Part 10: 1990;this equipment classification is called grade 1 (standard grade);b) equipment constructed in accordance with BS 638: Part 10: 1990 but calibrated to a higher standard of accuracy than required by BS 638: Part 10: 1990 and applied to tasks requiring greater precision of operation;this classification is called grade 2 (precision grade). The use of grade 2 (precision grade) validation or calibration is primarily determined by the requirements of the welding procedure and is to be specified by those responsible for the development or application of the welding procedure. The welding equipment covered in this standard includes: 1) welding power sources;2) wire feeders;3) welding instrumentation.