功率天平准直参数及其调整措施的分析

Analysis of Alignment Parameters and Its Adjusting Approaches for Watt Balance

质量量子基准的建立是计量科学领域的研究热点和难点。针对功率天平方案中准直部分进行了详细分析。首先介绍了功率天平的基本原理,并分析了功率天平实验中所涉及到的物理矢量;然后,结合NIST(NationalInstitute of Standard and Technology)功率天平线圈结构,给出了功率天平准直的物理含义,并通过对比理想情况与实际情况中功率天平的对应物理矢量的相互关系,分析了功率天平中存在的准直误差;根据功率天平研究的现状,总结了功率天平准直参数检测和调整的措施,并给出了对该领域研究最深入的英美两国在准直调整方面取得的研究成果;最后,详细分析了准直误差对中国计量科学研究院提出的能量天平方案的影响,并认为,前述准直参数检测和调整方法,对于其他国家功率天平以及能量天平准直参数的调整具有很好的借鉴意义。

Establishing quantum measurement standard for the unit of mass has always been a hot but also difficult research area in metrology science. Detailed analysis is put forward for the alignment of watt balance which is applied to redefine the unit of mass. Firstly, the principle of watt balance is given and all physical vectors involved in the watt balance theory are introduced. Then the NIST （National Institute of Standard and Technology） Watt balance is used as an example to illustrate the meaning of alignment in watt balance, and by comparing the relationship of all the vectors mentioned above in ideal and real condition possible alignment errors are discussed. According to the research of different metrology department around the world, a full description for measuring and reducing alignment error is brought out. Additional discussion about measurement errors which brought by misalignment of the NIM （National Institute of Metrology） joule balance is carried out. Finally, alignment adjusting procedures for NPL（National Physical Laboratory） watt balance and NIST watt balance are summarized. Methods list in this paper can be used for aligning both the watt balance and the NIM joule balance.