Similarly, resistance, Z, is proportional to the von Klitzing constant, [R.sub.K] = h/[e.sup.2], via the quantum Hall effect.
The last three constants are determined by other means, but are included since they are used in some of the other determinations Constant Symbol Planck constant h Josephson constant (SI) [K.sub.J] = 2e/h Electron mass [m.sub.e] Proton mass [m.sub.p] Avogadro constant [N.sub.A] Elementary charge e Josephson constant [K.sub.J-90] von Klitzing constant [K.sub.K-90] l/(fine-structure constant) l/[alpha] Rydberg constant [R.sub.[infinity]] Electron's atomic mass [m.sub.e]/[m.sub.u] Unc.
No effort was made to see how well the i = 2 dc quadruple-series QHR value of this poor-quality device approximates the 12 906.403 5 [ohm] von Klitzing constant [R.sub.K] since we were only investigating convergence of ac and dc values in this experiment, and would in any case not use ac1 as a standard.
Dziuba, Determination of the von Klitzing Constant and the Fine-Structure Constant Through a Comparison of the Quantized Hall Resistance and the Ohm Derived from the NIST Calculable Capacitor, Metrologia 35, 83-96 (1998).
Legal Ohm was re-defined in terms of the QHE, with the internationally-accepted value of the quantum Hall resistance (or von Klitzing constant, after the effect's discoverer) based on calculable ca pacitor experiments and other fundamental constant determinations.
The 1990 exact, conventional value of the von Klitzing constant,
The 1989 NIST value of the von Klitzing constant is [R.sub.K] = 25 812.807 23(61) [OMEGA], and the 1996 value is [R.sub.K] = 25 812.808 31(62) [OMEGA], which is larger by a fractional amount of 4.2 X [10.sup.-8].
where n and i are integers, e is the elementary charge, h is the Planck constant, f is the frequency of the microwave radiation applied to a Josephson device, [K.sub.J] is the Josephson constant, and [R.sub.K] is the von Klitzing constant.