论文信息 - Uncertainty Improvements of the NIST Electronic Kilogram

Uncertainty Improvements of the NIST Electronic Kilogram

<para> This paper summarizes the latest uncertainty improvements and data for a new result from the National Institute of Standards and Technology (NIST) electronic kilogram experiment. The result of 8 <formula formulatype="inline"><tex>$\pm$</tex></formula> 36 nW/W for the ratio <formula formulatype="inline"><tex>$ \{{W}_{90} /{W}- 1\}$</tex></formula>, as well as the Planck's constant, is comparable to the NIST 2005 value but with a lower uncertainty. Of the eight largest Type B uncertainty contributions, gravity acceleration, wheel surface, and reference mass magnetic susceptibility are considerably reduced. Humidity dependence in the recent data and limitations on the volt/velocity signal analysis are now the main limitations on the uncertainty. </para>

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