Measurements of the magnetic flux quantum, Planck constant, and elementary charge at VNIIM

Tests of an electromechanical system developed for measurements of the magnetic flux quantum, Planck's constant, and the elementary charge in SI units by a procedure based on a superconducting levitated mass have shown a precision of several parts in 10/sup 6/. When a special cryogenic measuring device is introduced into the system, the precision will increase to several parts in 10/sup 7/. Further improvements in the measuring setup should result in an uncertainty below 1 part in 10/sup 7/.<
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