ISO 21904-3:2018定义了一种实验室方法，用于测量焊炬上抽气系统的焊接烟尘捕集效率。该程序仅规定了一种方法，将测试参数的选择留给用户，以便评估不同变量的影响。 ISO 21904-3:2018适用于焊炬上的集成系统，以及在靠近电弧区域的焊炬上安装离散抽气系统的系统。该方法适用于所有连续焊丝焊接工艺、所有材料类型和所有焊接参数。 该方法可用于评估抽气流量、抽气喷嘴位置、保护气体流量、焊接几何形状、焊炬角度、烟气排放率等变量的影响。 ，关于捕获效率。

ISO 21904-3:2018 defines a laboratory method for measuring the welding fume capture efficiency of on-torch extraction systems. The procedure only prescribes a methodology, leaving selection of the test parameters to the user, so that the effect of different variables can be evaluated. ISO 21904-3:2018 is applicable to integrated on-torch systems and to systems where a discrete extraction system is attached to the welding torch close to the arc area. The methodology is suitable for use with all continuous wire welding processes, all material types and all welding parameters. The method can be used to evaluate the effects of variables such as extraction flow rate, extract nozzle position, shielding gas flow rate, welding geometry, welding torch angle, fume emission rate, etc., on capture efficiency.