2-Terminal Coaxial Capacitance Measurements and Cable Corrections

Coaxial 2-terminal bridge comparison is a widely used metrological method in the dissemination of value of capacitance up to 1000 pF and $10^4$ rad/s. In this range, capacitance can be measured with uncertainties as small as few parts in $10^{7}$; however, such measuments must take into account the corrections due to the impedance of cables, connectors and ports, which can tipically amount up to $10^{-8}$ $\mu$F/F $-$ and maybe larger. In this work, we report on how correction factors in 2-terminal pair coaxial bridge capacitance measurements are presently measured and calculated at Inmetro.