The Performance of the KIBB-g1 Tabletop Kibble Balance at NIST

A tabletop-sized Kibble balance (KIBB-g1) designed to directly realize mass at the gram-level range with uncertainties on the order of parts in 10$^6$ has been developed at the National Institute of Standards and Technology (NIST). The masses of a nominally 5,g and 1,g weight were determined with 1-$sigma$ standard uncertainties of 9.0,$upmu$g and 6.7,$upmu$g, respectively. The corresponding relative uncertainties are $1.8times 10^{-6}$ and $6.3times 10^{-6}$. The construction of the instrument, capabilities, and full uncertainty budgets are presented in this manuscript.