Progress on accurate measurement of the Planck constant: Watt balance and counting atoms <xref ref-type="fn" rid="cpb141896fn1">*</xref>

Progress on accurate measurement of the Planck constant: Watt balance and counting atoms *

Li Shi-Song^a),^b),^†, Zhang Zhong-Hua^b),^‡, Zhao Wei^a), Li Zheng-Kun^b), Huang Song-Ling^a)

Fig. 2. Schematic of the NPL-NRC watt balance. 1: central knife-edge, 2: central flat, 3: balance beam, 4: end knife-edge, 5: stirrup, 6: suspension middle section, 7: lower gimbal, 8: suspension lower section, 9: test mass, 10: mass pan, 11: permanent magnet, 12: coil, 13: interferometer, 14: voice coil, 15: tare mass. [ 48 ]