Determination of2e/hand h/e2in SI units

Recent determinations of the volt and the quantized Hall resistance at the Australian National Measurement Laboratory have yielded values having sub-ppm uncertainties for a number of important fundamental constants. The direct experimental results are 2e/h=483.597 90(15) THz ${\mathrm{V}}^{\mathrm{-}1}$ and h/$e^2$=25 812.809 9(20) Ω, both in SI units. Derived values are given for the electron charge, Planck’s constant, the magnetic flux quantum, and the inverse fine-structure constant.