This part of ISO 15012 specifies a method for establishing the minimum air volume flow rate required for captor hoods and nozzles to effectively capture fume and gases from welding and allied processes. The method can be used with capture devices of any aspect ratio and cross-sectional area, but it is not applicable to on-gun extraction systems and down draught tables. This part of ISO 15012 also specifies the test data to be marked on the capture devices.