本文件规定了粒度加权细分数（SWFF）和粒度加权的测定 通过计算得到的大块材料中结晶二氧化硅（SWFFCS）的细分数。文件也 指定此方法有效所需满足的假设和前提条件。购买本文件时可获得的所有当前修订均包含在购买本文件中。

This document specifies the determination of the size-weighted fine fraction (SWFF) and the sizeweighted fine fraction of crystalline silica (SWFFCS) in bulk materials by calculation. The document also specifies the assumptions and preconditions to be fulfilled for this method to be valid.All current amendments available at time of purchase are included with the purchase of this document.