The scientific and technological advances in the last 50 years leads to large variations in the metrology. Recently discovered stable microscopic processes and macroscopic quantum phenomena ( AC Josephson voltage, Klitzing resistance, etc. ) make possible very high accuracy measurements. As a result of these developments, classical definitions of SI basic units entered into a conflict with the modern science. The need to change the International Metric System has emerged.
Watt balances plays an important role In the process of the SI redefinition. Excessive complexity of existing watt balances ( NPL-NRC, NIST, METAS, BIPM, LNE, KRİSS, MSL ) not only restrict the accuracy of the Planck constant measurements but represents a serious drawback for primary realization of the kilogram in NMI also. Unlike the traditional moving coil watt balances the UME oscillating magnet watt balance has very little complexity. High accuracy, small sizes, low cost, easy-to-use and maintain are main advantages of the UME watt balance. The first stage purpose of the UME watt balance project is to achieve the performance of the NIST1 watt balance., in the second stage of the project the Planck constant is aimed to measure with accuracy better than the METAS 2012 result.
(in Process)