Uncertainty Analysis on the Magnetic System of Joule Balance, a Quantum Mass Standard
HAN Bing1,2,HE Qing3,LI Zheng-kun3,LI Chen4
1.College of Precision Instrument and OptoElectronics Engineering, Tianjin University,Tianjin 300072,China
2.College of Quality and Supervisor technology, Hebei University, Baoding, Hebei 071002,China
3.National Institute of Metrology, Beijing 100013,China
4.Department of Precision Instruments and Mechanology,Tsinghua University, Beijing 100084,China
Abstract：Based on the special structure of exciting coils system of Joule balance, the uncertainty sources of the magnetic density in the geometrical center of magnetic field was analysed and evaluated.The relative combined standard uncertainty of magnetic field in ΔH/H was 1.8×10-3 In addition, it was proved that the largest components of uncertainty were due to terms with u(I),which was 1.8×10-3 contribution to relative combined standard uncertainty in ΔH/H.Therefore the high-precision constant-current source was recommended to reduce uncertainty of magnetic field of Joule Balance.
韩冰,贺青,李正坤,李辰. 焦耳天平（量子质量基准）磁场系统的不确定度分析[J]. 计量学报, 2011, 32(2): 152-157.
HAN Bing,HE Qing,LI Zheng-kun,LI Chen. Uncertainty Analysis on the Magnetic System of Joule Balance, a Quantum Mass Standard. Acta Metrologica Sinica, 2011, 32(2): 152-157.
1］Kibble B P.A measurement of the gyromagnetic ratio of the proton by the strong field method［C］// Atomic Masses and Fundamental Constants,New York: Plenum,1976.
［2］Robinson I A, Kibble B P. The NPL moving-coil apparatus for measuring Planck"s constant and monitoring the kilogram［J］.IEEE Trans Instrum Meas, 1997, 46(2): 596-600.
［3］Mills I M,Mohr P J,Terry J Q,et al.Redefinition of the kilogram: a decision whose time has come［J］.Metrologia,2005,42(2) :71-80.
［4］Steiner R L，Williams E R, Newell D B,et al.Towards an electronic kilogram: an improved measurement of the Planck constant and electron mass［J］.Metrologia,2005, 42(5):431-441.
［5］Brown G V,Flax L.Superposing of semiinfinite solenoids for calculating magnetic fields of thick solenoids［J］.Appl Phy, 1962,35(2):65-70.
［6］Zhang Z, He Q, Li Z.An approach for improving the watt balance［C］//Filippo LEVI and Macro PISANI, CPEM2006,Torino, Italy,2006.
［7］JJF 1059—1999,Guide to estimate the measurement uncertainty［S］.
2011, Vol. 32 
