检定介质制备与静力称重法容量测量不确定度研究

Study on Uncertainty of Volume Measerment by Hydrostatic Weighing Method and Production of Calibration Medium

采用微滤反渗透电去离子法制备超纯水代替自来水做为容量计量的检定介质。测量水的氢氧同位素丰度、温度梯度和大气环境参数，进行纯水密度计算的同位素丰度、压缩修正及溶解空气修正。水样检测结果表明，所制水符合GB／T11446．1EW—I水标准。水密度测量的标准不确定度减小到7×1013kg／m3，容量基准的容量测量不确定度“。小于3×10^（-5）（k=3）。

To propose that high-purity water which producted by micro-filter, recerse osmosis and electrodeionzation technology is used as calibration medium and as a substitute for tap-water. To correcte the density of water for factors as the water isotopic abundance, teperature gradient and dissolved air, the isotopic abundance, teperature gradient and atmosphere environmental parameters （t, p, RH） are measured. The water quality report shows that the water be producted is in accord with the GB/T 11446. 1 EW-I standard. The standard measurement uncertainty of water density is reduced to 7 x 10-3 kg/ m3 , and the measurement uncertainty of the volume primary standard Ure1 is less than 3 x 10 -5 （ k = 3 ）.