A new four terminal-pair bridge for traceable impedance measurements at frequencies up to 1 MHz

A new four terminal-pair bridge has been developed and used for traceable measurement of capacitance and resistance at frequencies up to 1 MHz. The apparent capacitance of a gas-filled 100-pF standard agrees with calculated values to better than 200 μF/F at 1 MHz. This is an order of magnitude improvement on existing capabilities at NPL. The frequency dependence of the dissipation factor of capacitance standards is discussed, and the capacitance and dissipation factor of ceramic NPO-dielectric standards has also been measured. The frequency dependence measurements of the calculable coaxial 100-Ω and 1-kΩ resistance standards are also presented