低温热分析标准物质的研制

研制了两种0~100℃热分析标准物质,分别为金属镓和水杨酸苯酯标准物质。研制的标准物质具有良好的均匀性和稳定性,采用与NIST,LGC相应标准物质比较的方法定值。NIST为SRM 2234镓,其定值采用288.6~314.35 K范围内的绝热热量计测得温度及热量值;LGC用绝热法为水杨酸苯酯的熔化温度和熔化热定值,两种方法都可以直接溯源至SI单位。对定值结果的不确定度进行了分析和评定。镓和水杨酸苯酯标准物质的熔化温度分别为(29.77±0.20)℃(k=2),(41.81±0.34)℃(k=2);熔化热分别为(80.52±0.48)J/g(k=2),(88.94±0.62)J/g(k=2)。研制的两种标准物质满足国家标准物质的技术要求,申报已获批准。

Development of Certiifed Reference Material for Low Temperature Thermal Analysis

Two kinds of thermal analysis certified refence materials were developed, which were gallium and phenyl salicylate refence materials, respectively. The two refence materials had good uniformity and stability,whose results were compared with the standard reference material of NIST and LGC. The certified values of NIST SRM 2234 were obtained from adiabatic calorimetric measurements in the temperature range of 288.6 K to 314.35 K. LGC used adiabatic calorimeter to determine the enthalpy and melting temperature of phenyl salicylate,two kinds of methods could be directly traced to SI units. The fusion temperature of gallium and phenyl salicylate refence materials were （29.77±0.20）℃（k=2）, （41.81±0.34）℃（k=2） , respectively, and fusion enthalpy were （80.52±0.48） J/g （k=2）,（88.94±0.62） J/g （k=2）, respectively. The two CRMs can meet the requirements of the national standard material technology,and has been declared as national certified reference materials.