Measurement of the Planck constant at the National Institute of Standards and Technology from 2015 to 2017

Abstract

Researchers at the National Institute of Standards and Technology(NIST) have measured the value of the Planck constant to be $h=6.626069934(89)\times 10^{-34}$Js (relative standard uncertainty $13\times 10^{-9}$). The result is based on over 10000 weighings of masses with nominal values ranging from 0.5kg to 2kg with the Kibble balance NIST-4. The uncertainty has been reduced by more than twofold relative to a previous determination because of three factors: (1) a much larger data set than previously available, allowing a more realistic, and smaller, Type A evaluation; (2) a more comprehensive measurement of the back action of the weighing current on the magnet by weighing masses up to 2kg, decreasing the uncertainty associated with magnet non-linearity; (3) a rigorous investigation of the dependence of the geometric factor on the coil velocity reducing the uncertainty assigned to time-dependent leakage of current in the coil.

11 pages 5 figures, published in metrologia

References in corpus (2)

• Construction, Measurement, Shimming, and Performance of the NIST-4 Magnet System
• A summary of the Planck constant measurements using a watt balance with a superconducting solenoid at NIST

Cited by in corpus (7)

• The ampere and the electrical units in the quantum era
• The irony of the magnet system for Kibble balances -- a review
• Magnet system for the Quantum Electro-Mechanical Metrology Suite
• Hidden Symmetries in Deformed Very Special Relativity
• Scientific value of the quantum tests of equivalence principle in light of Hilbert's sixth problem
• Resolution of the paradox of the diamagnetic effect on the Kibble coil
• A Simple Improvement for Permanent Magnet Systems for Kibble Balances: More Flat Field at Almost No Cost