表观挥发物含量是加热时损失的物质相对于初始质量的百分比，规定方法的原理是通过测量试样在空气通风烘箱中以规定温度加热规定时间后的质量变化来获得。该方法适用于所有单向和多向纤维增强预浸料以及所有热固性树脂基体。不适用于未经处理的增强纤维。

The apparent volatile-matter content is the percentage of matter lost on heating, relative to the initial mass, The principle of the method specified is obtaining it by measuring the change in mass of a test specimen when heated in an air-ventilated oven at a specified temperature for a specified length of time. The method is applicable to all unidirectional and multidirectional fibre-reinforced prepregs and all thermosetting-resin matrices. Does not apply to unimpregnated reinforcement fibres.