1.1 本规程旨在帮助个人在工作环境中对单晶陶瓷晶须（SCCW）进行采样和分析，例如碳化硅和氮化硅。它描述了用于评估空气中SCCW浓度和粒度分布的采样和分析技术，这些浓度和粒度分布可能发生在制造、加工、运输或使用这些材料的工作场所内和周围。 1.2 目前用于石棉和其他纤维材料的协议已被用作制定取样和分析程序的指南，以表征SCCW制造和使用过程中产生的纤维。 本文所述的采样和分析协议是专门针对SCCW编写的，但是，它们可能适用于其他人造矿物纤维（MMMF）。 1.3 以国际单位制表示的数值应视为标准。括号中给出的值仅供参考。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 5.1 SCCW可能存在于制造、加工、运输或使用这些材料的工作场所大气中。本规程中讨论的测试方法可用于在这些环境中监测空气中SCCW浓度时提供指导。 5.2 由于其可见性限制，PCM或SEM可能无法检测到一些样品中存在的很大一部分非常小的薄纤维。因此，TEM被认为是分析机载SCCW的参考技术。 当样品来自以前没有特征的工作场所或材料时，必须使用透射电镜来确定纤维数量和形态。 5.3 虽然TEM是参考技术，但PCM或SEM被认为是分析机载SCCW的主要筛选方法。 5.4 至少在最初，应进行平行TEM测量，以提供PCM或SEM看到的总纤维部分的指数或相对测量值。只有在该百分比处于高且可再现水平的情况下，才能完全依赖低分辨率技术（即PCM或SEM）。

1.1 This practice is intended to assist individuals in the sampling and analysis of single-crystal ceramic whiskers (SCCW), such as silicon carbide and silicon nitride, in the workplace environment. It describes sampling and analytical techniques used to assess the airborne concentration and size distribution of SCCW, which may occur in and around the workplace where these materials are manufactured, processed, transported, or used. 1.2 The protocols currently in use for asbestos and other fibrous materials have been used as a guide in developing sampling and analytical procedures for characterizing fibers produced from the manufacture and use of SCCW. The sampling and analysis protocols described here have been written specifically for SCCW, however, they may be appropriate for other man-made mineral fibers (MMMF). 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. ====== Significance And Use ====== 5.1 The SCCW may be present in the workplace atmosphere where these materials are manufactured, processed, transported, or used. The test methods discussed in this practice can be used to provide guidance when monitoring airborne concentrations of SCCW in these environments. 5.2 Because of their visibility limitations, a significant fraction of the very small thin fibers that are present in some samples may not be detected by PCM or SEM. Therefore, TEM is considered to be the reference technique for the analysis of airborne SCCW. The TEM must be used to determine both fiber count and morphology when samples are from previously uncharacterized workplaces or materials. 5.3 Although TEM is the reference technique, PCM or SEM are considered to be the primary screening methods for the analysis of airborne SCCW. 5.4 Parallel TEM measurements shall be carried out, at least initially, to provide an index or relative measure of the fraction of total fibers that are seen by PCM or SEM. Only in instances when this percentage has been shown to be at a high and reproducible level may the lower resolution techniques (that is, PCM or SEM) be relied on exclusively.