电镜能谱仪认定火灾起火点研究

Research on determination of the origin of fire by SEM/EDAX

介绍烧毁严重程度认定法、烟熏痕迹认定法等起火点的认定方法。以烧毁严重程度判别起火部位或起火点受火灾荷载的干扰,其科学性与准确度受到质疑。电镜能谱认定起火点的方法基于起火点受热时间最长,在同类别灰烬中的碳含量最低的原理。以粉碎的A4打印纸充当可燃物设计实验,利用电镜能谱仪辨识灰烬类别,测定碳含量,确定火灾蔓延方向及起火点,验证电镜能谱认定法的可行性。结果表明,灰烬样本在经实验室电炉600℃灼烧2h后仍能够检测出≥2%的碳元素;选择能谱面分析误差较小;检测点的灰烬必须是相同类别的灰烬。介绍电镜能谱仪认定起火点的步骤。

The identification of fire starting point by burn severity and smoke trail was introduced.The identification of fire starting point was influenced by fire load,its scientificity and accuracy are questioned.The identification of fire starting point by electron microscopy is based on the fact that the heating time of the origin of fire is the longest and its carbon content is the lowest among the same type of ashes.Taking shattered A4 paper as combustible materials,SEM/EDAX was used to identify the type of ashes,determine the carbon content and the fire spread direction,and thus determine the origin of fire.The feasibility of determining the fire spot by SEM/EDAX was verified.Results showed that,the sample ashes can be tested by carbon concentration≥2% after 2h,600℃ burning by electric furnace in laboratory.The error is little in plane analysis of energy spectrum.The ashes be tested must be the same category.The procedure of identification of fire starting point by SEM/EDAX was introduced also.