Characterisation of resistance and capacitance standards up to 1 MHz

New four terminal-pair resistance and capacitance impedance standards are being fabricated for use at high frequencies ranging from 10 kHz to 1 MHz. The standards have been designed to ensure low frequency dependence of their impedance up to 1 MHz. A brief outline of the fabrication of the standards is described. A high frequency four terminal-pair impedance ratio bridge used to characterise these standards is also discussed.