Fabrication of Capacitor–Resistor Bank for Calibrating Commercial Capacitance and Tan $delta $ Measuring Bridges

摘要

A capacitor–resistor combined bank to calibrate both the capacitance ratio and dissipation factor over the whole range for commercial capacitance and tan measuring bridges was fabricated. A fabricated secondary working standard for capacitance ratio calibration was realized by connecting double-shielded capacitors in parallel employing a substitution and build-up technique, while a secondary working standard for dissipation factor calibration was attained by connecting shielded capacitors in parallel with a shielded T-resistor network. The design of the capacitor–resistor bank and calibration results for the two commercial bridges are presented and compared with specifications provided by manufacturers including the measurement uncertainty.