环境空气.无机纤维颗粒数值浓度的测定.扫描电子显微镜法

[中文适用范围]： 本文件规定了一种使用扫描电子显微镜测定空气中无机纤维颗粒浓度的方法。 该方法规定使用镀金、毛细孔、径迹蚀刻的膜过滤器，通过该膜过滤器吸入已知体积的空气。 使用能量色散X射线分析，该方法可以区分成分与石棉品种（例如蛇纹石和角闪石）、石膏和其他无机纤维一致的纤维。 附录 C 总结了可测量的光纤类型。 本文件适用于环境空气中无机纤维颗粒浓度的测量。 该方法还适用于测定建筑物内部大气中无机纤维颗粒的数值浓度，例如测定去除含石棉产品后残留的空气中无机纤维颗粒的浓度。 在标准测量条件（见 7.2）下可检测的宽度范围内，长度大于 5 µm 的纤维的浓度范围约为每平方毫米过滤面积 3 至 200 根纤维。 这些值代表的空气浓度（以每立方米纤维数为单位）是采样空气体积的函数。 该方法检测和分类宽度小于 0.2 µm 的纤维的能力有限。 如果被采样的大气中的空气纤维主要是 [外文原描述]： This document specifies a method using scanning electron microscopy for determination of the concentration of inorganic fibrous particles in the air. The method specifies the use of gold-coated, capillary-pore, track-etched membrane filters, through which a known volume of air has been drawn. Using energy-dispersive X-ray analysis, the method can discriminate between fibres with compositions consistent with those of the asbestos varieties (e.g. serpentine and amphibole), gypsum, and other inorganic fibres. Annex C provides a summary of fibre types which can be measured. This document is applicable to the measurement of the concentrations of inorganic fibrous particles in ambient air. The method is also applicable for determining the numerical concentrations of inorganic fibrous particles in the interior atmospheres of buildings, for example to determine the concentration of airborne inorganic fibrous particles remaining after the removal of asbestos-containing products. The range of concentrations for fibres with lengths greater than 5 µm, in the range of widths which can be detected under standard measurement conditions (see 7.2), is approximately 3 fibres to 200 fibres per square millimetre of filter area. The air concentrations, in fibres per cubic metre, represented by these values are a function of the volume of air sampled. The ability of the method to detect and classify fibres with widths lower than 0,2 µm is limited. If airborne fibres in the atmosphere being sampled are predominantly <0,2 µm in width, a transmission electron microscopy method such as ISO 10312 [ 8 ] can be used to determine the smaller fibres.