【摘要】 能量天平法已在中国计量科学研究院开展了几年的研究。研究的目的与功率天平法是一致的,即通过测量普朗克常数来建立质量量子基准,但具体方法不同。2010年以来该项研究取得一定进展。例如对于直流互感量测量这一关键问题,已研究出一种新的方波补偿方法,测量不确定度达到10^-7量级（k=1）。还研发了一种涡流传感器,可更准确地对可动线圈定位。线圈系统的准直问题也得到进展,研制了一种油阻尼器,大大减小了由于天平基础振动和线圈加热上升气流引起的线圈抖动。这些措施改善了线圈位置及互感测量的不确定度。测量普朗克常数h的最新结果为6.626104（59）×10^-34J·s,综合的相对不确定度为8.9×10^-6（k=1）。对所遇到的困难和进一步的改进措施也在文中进行了讨论。更多还原

【Abstract】 The National Institute of Metrology（NIM） has been studying the Joule Balance method（which is used for the same purpose as the Watt Balance method but operated differently）,for several years to establish a kind of quantum mass standard by means of measuring the Planck constant.Since 2010,some progress has been achieved.A new standard square wave compensation method has been developed to measure the DC mutual inductance with an uncertainty of several parts in10^-7（k = 1）.An eddy current sensor for positioning has been designed and implemented to obtain a more accurate position of the movable coil.The alignment technique for the coil system has also been placed under consideration.Specifically,a newly developed oil damping device reduces the small swing of the coil set which occurs because of a combination of the weak vibration of the balance base and the hot ascending warm air from the current heating of coils.As a result,the measurement uncertainty of the coil position and mutual inductance is improved..The recent measurement result of the Planck constant h is6.626104（59） × 10^-34 J·s with an uncertainty of 8.9 × 10 ^-6（k = 1）.Further improvements and difficulties are also discussed.更多还原