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| 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 |
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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.
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2011, Vol. 32 
