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. 4. Apparatus of the NIST-3 watt balance. [ 4 ]