This standard specifies requirements for calibration, verification and validation of equipment used to: ¾ð control of process variables during fabrication; and ¾ð control of the properties of equipment used for welding or welding allied processes; where the resulting output cannot be readily or economically documented by subsequent monitoring, inspection and testing. This regards process variables influencing the fitness-for-purpose and in particular the safety of the fabricated product NOTE 1 The standard is based on the lists of process variables stated in standards for specification of welding procedures, in particular, but not exclusively on the ISO 15609 series of standards. Future revisions of these standards can result in addition or deletion of parameters considered necessary to specify. Some guidance is, in addition, given in annex B as regards requirements for calibration; verification and validation as part of acceptance testing of equipment used for welding or allied processes. Requirements to calibrate, verify and validate as part of inspection, testing, non-destructive testing or measuring of final welded products performed in order to verify confirm product compliance are outside the scope of the present standard. The subject of the standard is limited to calibration, verification and validation of equipment after installation, as part of the workshops schemes for maintenance and/or operation. NOTE 2 It should be stressed that the standard has nothing to do with manufacture and installation of equipment for welding. Requirements to new equipment are formulated in directives and product codes (standards), as necessary.