標準號：BS ISO 13794-1999
中文標準名稱：環境空氣.石棉纖維的測定.間接傳遞電子顯微鏡法
英文標準名稱：Ambient air - Determination of asbestos fibres - Indirect-transfer transmission electron microscopy method
標準類型：Z15
發布日期：1999/11/15 12:00:00
實施日期：1999/11/15 12:00:00
中國標準分類號：Z15
國際標準分類號：13.040.20
適用范圍：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