1.1本试验方法涵盖了用于评估单晶陶瓷晶须（SCCW）空气中浓度的采样方法和分析技术，如碳化硅和氮化硅，这些物质可能发生在制造、加工、运输或使用这些材料的工作场所内和周围。本试验方法基于通过过滤器过滤已知量的空气来收集纤维。随后使用相衬显微镜（PCM）评估过滤器，以确定满足适当选择的计数标准的纤维数量。该测试方法无法区分不同类型的纤维。本试验方法可能适用于其他人造矿物纤维（MMMF）。 1.2本试验方法适用于收集过滤器上大于5的纤维的定量 μ 长度m，小于3 μ 宽度为m，纵横比等于或大于5:1。这些数据可以直接转换为每单位体积采样空气的浓度声明。 该测试方法受到PCM可见纤维直径的限制（通常大于0.25 μ m）和重合干涉粒子的数量和类型。 1.3可能需要进行更明确的分析，以确认与PCM一起定位的光纤的特性和尺寸，尤其是在可能存在其他类型光纤的情况下。此类技术可包括扫描电子显微镜（SEM）或透射电子显微镜（TEM）。实践中描述了使用这些试验方法识别和确定SCCW的尺寸 D6058 和试验方法 D6059 和 D6056 . 1.4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。 1.5 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====== 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。该测试方法可用于监测这些环境中空气中纤维的浓度。它可以作为个人或区域监控策略的一部分。 本试验方法仅基于尺寸考虑。因此，它不能对所计数的纤维进行正面识别。当需要额外的纤维识别信息时，需要通过SEM或TEM进行分析。 笔记 1-本试验方法假设分析员熟悉PCM仪器的操作和使用该技术获得的数据的解释。 本试验方法不适用于直径小于约0.25的纤维的测量 μ m，因为与PCM相关的可见性限制。如果需要，可以使用SEM或TEM方法提供SCCW的额外尺寸信息（参考实践 D6058 有关使用这些方法的更多信息）。 应报告使用本试验方法的结果以及所研究样品的95%置信限。单个实验室应确定其实验室内变异系数，并将其用于报告95%置信限 (1,3,4) .

1.1 This test method covers the sampling methods and analysis techniques used to assess the airborne concentration of single-crystal ceramic whiskers (SCCW), such as silicon carbide and silicon nitride, which may occur in and around the workplace where these materials are manufactured, processed, transported, or used. This test method is based on the collection of fibers by filtration of a known quantity of air through a filter. The filter is subsequently evaluated with a phase contrast microscope (PCM) for the number of fibers meeting appropriately selected counting criteria. This test method cannot distinguish among different types of fibers. This test method may be appropriate for other man-made mineral fibers (MMMF). 1.2 This test method is applicable to the quantitation of fibers on a collection filter that are greater than 5 μ m in length, less than 3 μ m in width, and have an aspect ratio equal to or greater than 5:1. The data are directly convertible to a statement of concentration per unit volume of air sampled. This test method is limited by the diameter of the fibers visible by PCM (typically greater than 0.25 μ m in width) and the amount and type of coincident interference particles. 1.3 A more definitive analysis may be necessary to confirm the identity and dimensions of the fibers located with the PCM, especially where other fiber types may be present. Such techniques may include scanning electron microscopy (SEM) or transmission electron microscopy (TEM). The use of these test methods for the identification and size determination of SCCW is described in Practice D6058 and Test Methods D6059 and D6056 . 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 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 ====== The SCCW may be present in the workplace atmosphere where these materials are manufactured, processed, transported, or used. This test method can be used to monitor airborne concentrations of fibers in these environments. It may be employed as part of a personal or area monitoring strategy. This test method is based on dimensional considerations only. As such, it does not provide a positive identification of the fibers counted. Analysis by SEM or TEM is required when additional fiber identification information is needed. Note 1—This test method assumes that the analyst is familiar with the operation of PCM instrumentation and the interpretation of data obtained using this technique. This test method is not appropriate for measurement of fibers with diameters less than approximately 0.25 μ m due to visibility limitations associated with PCM. The SEM or TEM methods may be used to provide additional size information of SCCW if needed (refer to Practice D6058 for additional information on the use of these methods). Results from the use of this test method shall be reported along with 95 % confidence limits for the samples being studied. Individual laboratories shall determine their intralaboratory coefficient of variation and use it for reporting 95 % confidence limits (1,3,4) .