BS ISO 13794-1999 环境空气.石棉纤维的测定.间接传递电子显微镜法

标准号：BS ISO 13794-1999
中文标准名称：环境空气.石棉纤维的测定.间接传递电子显微镜法
英文标准名称：Ambient air - Determination of asbestos fibres - Indirect-transfer transmission electron microscopy method
标准类型：Z15
发布日期：1999/11/15 12:00:00
实施日期：1999/11/15 12:00:00
中国标准分类号：Z15
国际标准分类号：13.040.20
适用范围：1 Substance determined This International Standard specifies a reference method using transmission electron microscopy (TEM) for determination of the concentration of asbestos structures in ambient atmospheres. The specimen preparation procedure incorporates ashing and dispersion of the collected particulate, so that all asbestos is measured, including the asbestos originally incorporated in particle aggregates or particles of composite materials. The lengths, widths and aspect ratios of the asbestos fibres and bundles are measured, and these, together with the density of the type of asbestos, also allow the total mass concentration of airborne asbestos to be calculated. The method allows determination of the type(s) of asbestos fibre present. The method cannot discriminate between individual fibres of the asbestos and non-asbestos analogues of the same amphibole mineral. 2 Type of sample The method is defined for polycarbonate capillary-pore filters or cellulose ester (either mixed esters of cellulose or cellulose nitrate) filters through which a known volume of air has been drawn. The method is suitable for determination of asbestos in both exterior and building atmospheres. 3 Range The upper limit for the range of concentration that can be measured on the analytical filter is 7 000 structures/mm