1.1 本试验方法包括以下步骤:( 一 )确定灰尘中的石棉和( b )提供采样粉尘中石棉表面负荷的估计值，报告为采样表面单位面积的石棉结构数量。 1.1.1 如果要确定石棉质量的估计值，请参考试验方法 D5756 . 1.2 本试验方法描述了通过微真空技术对石棉结构水平的非空气粉尘进行采样所需的设备和程序。非气载样品在标准滤膜盒内收集，从可能含有石棉的粉尘表面区域取样。 1.2.1 该程序使用了显微视觉采样技术。这种技术的收集效率未知，并且会因基质而异。影响收集效率的特性包括表面纹理、粘附性、静电特性和其他因素。 1.3 通过透射电子显微镜（TEM）鉴定的石棉基于形态学、选区电子衍射（SAED）和能量色散X射线分析（EDXA）。还确定了有关结构尺寸的一些信息。 1.4 本试验方法通常适用于从每平方厘米约1000个石棉结构开始估算石棉结构的表面载荷。 1.4.1 本试验方法中概述的程序采用间接样品制备技术。其目的是将聚集的石棉分散成基本的原纤维、纤维束、簇或基质，这些原纤维、纤维束、簇或基质可以通过透射电子显微镜更准确地定量。然而，与所有间接样品制备技术一样，为量化而观察到的石棉可能并不代表采样时石棉的物理形态。更具体地说，所述程序既不会产生也不会破坏石棉，但可能会改变矿物纤维的物理形态。 1.5 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。 1.6 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 这种微量采样和间接分析方法用于石棉非空气粉尘样品的一般测试。它用于帮助评估建筑物表面上可能发现的灰尘，如天花板、架子、电气部件、管道工程、地毯等。该测试方法提供了从定量TEM分析得出的石棉结构在单位面积灰尘中的表面负荷指数。 5.1.1 本试验方法未描述评估含石棉材料建筑物的安全性或可居住性，或是否符合联邦、州或地方法规或法令所需的程序或技术。用户有责任做出这些决定。 5.1.2 目前，通过本试验方法测量的含石棉粉尘与人类暴露于空气中石棉的潜在风险之间尚未建立任何关系。因此，用户在解释从本试验方法获得的数据时应考虑其他可用信息。 5.2 尘埃的这个定义接受所有小到足以通过1的粒子- 毫米（18号）屏幕。因此，在样品制备过程中分散的单个大型含石棉颗粒（来自粒径分布的大端）可能会导致该样品的TEM分析中产生异常大的石棉表面负载。因此，建议从同一区域获得多个独立样本，并在整个程序中至少分析三个样本。

1.1 This test method covers a procedure to ( a ) identify asbestos in dust and ( b ) provide an estimate of the surface loading of asbestos in the sampled dust reported as the number of asbestos structures per unit area of sampled surface. 1.1.1 If an estimate of the asbestos mass is to be determined, the user is referred to Test Method D5756 . 1.2 This test method describes the equipment and procedures necessary for sampling, by a microvacuum technique, non-airborne dust for levels of asbestos structures. The non-airborne sample is collected inside a standard filter membrane cassette from the sampling of a surface area for dust which may contain asbestos. 1.2.1 This procedure uses a microvacuuming sampling technique. The collection efficiency of this technique is unknown and will vary among substrates. Properties influencing collection efficiency include surface texture, adhesiveness, electrostatic properties and other factors. 1.3 Asbestos identified by transmission electron microscopy (TEM) is based on morphology, selected area electron diffraction (SAED), and energy dispersive X-ray analysis (EDXA). Some information about structure size is also determined. 1.4 This test method is generally applicable for an estimate of the surface loading of asbestos structures starting from approximately 1000 asbestos structures per square centimetre. 1.4.1 The procedure outlined in this test method employs an indirect sample preparation technique. It is intended to disperse aggregated asbestos into fundamental fibrils, fiber bundles, clusters, or matrices that can be more accurately quantified by transmission electron microscopy. However, as with all indirect sample preparation techniques, the asbestos observed for quantification may not represent the physical form of the asbestos as sampled. More specifically, the procedure described neither creates nor destroys asbestos, but it may alter the physical form of the mineral fibers. 1.5 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.6 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 This microvacuum sampling and indirect analysis method is used for the general testing of non-airborne dust samples for asbestos. It is used to assist in the evaluation of dust that may be found on surfaces in buildings such as ceiling tiles, shelving, electrical components, duct work, carpet, etc. This test method provides an index of the surface loading of asbestos structures in the dust per unit area analyzed as derived from a quantitative TEM analysis. 5.1.1 This test method does not describe procedures or techniques required to evaluate the safety or habitability of buildings with asbestos-containing materials, or compliance with federal, state, or local regulations or statutes. It is the user’s responsibility to make these determinations. 5.1.2 At present, no relationship has been established between asbestos-containing dust as measured by this test method and potential human exposure to airborne asbestos. Accordingly, the users should consider other available information in their interpretation of the data obtained from this test method. 5.2 This definition of dust accepts all particles small enough to pass through a 1-mm (No. 18) screen. Thus, a single, large asbestos containing particle(s) (from the large end of the particle size distribution) dispersed during sample preparation may result in anomalously large asbestos surface loading results in the TEM analyses of that sample. It is, therefore, recommended that multiple independent samples are secured from the same area, and that a minimum of three samples be analyzed by the entire procedure.