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. 15. Summary of numeral determinations of the Planck constant with relative uncertainties smaller than 1 #cod#x000D7; 10 #cod#x02212;6 . KJ, WB, and NA present the result obtained from the voltage balance, the watt balance, and the Avogadro project.