Abstract The principle of density measurement by hydrostatic weighing method and the characteristic formula of pure water density in volume measurement were analyzed, and the calculation formula of liquid density measured by solid standard of known density was deduced. The weighing method assigned a value to the solid density standard silicon sphere, and the relative measurement uncertainty was 3×10-6 (k=2). Finally, using a high-precision liquid density measuring device at 20℃, the density of the solid standard (silicon sphere) was transferred to the density of pure water by static weighing method. Compared with the Tanaka model, the En value was 0.059, and the comparison results were equivalent. The experimental results not only verify the high-precision liquid density measurement device, but also verify the theoretical value of the 20℃ pure water density model.
Tanaka M, Girard G, Davis R, A. et al. Recommended table for the density of water between 0℃ and 40℃ based on recent experimental reports［J］. Metrologia, 2001, 38(4):301-309.
Zhang L L, Kuramoto N, Kurokawa A, et al. XPS study of silicon spheres as a density standard［J］. Surface and Interface Analysis, 2019, 51(4):127.
Ju Y F,Wang J B,Chang C Y, et al. Monte Carlo Method for the Measurement Uncertainty Evaluation Considering Non-positive Definite Correlation. Acta Metrologica Sinica, 2022, 43(6):830-836.
［1］
韩雨桐. SI基本单位与时间计量［J］. 计量学报, 2022, 43(1):1-6.
Ma A W, Qu X H. The Quantized Redefinition of the SI and its Signification［J］. Acta Metrologica Sinica, 2020, 41(2): 129-133.
Zhong J D, Sun B, Zhao Y X, et al. Calibration Method for Optical Measurement of Ultra-Micro Liquid Volume［J］. Acta Metrologica Sinica, 2020, 41(8): 960-964.
［21］
Batista E, Paton R. The selection of water property formulae for volume and flow calibration［J］. Metrologia, 2008, 44(6):127.
Peng C, Wang J. Research on High Accuracy Mass Measurement of Silicon Sphere in the Dissemination of Mass Unit［J］. Acta Metrologica Sinica, 2021, 42(3):265-270.
2023, Vol. 44 
