Guildline Instruments 9910A High Voltage Capacitance Bridge is a measurement standard employing the AC Current Comparator principle. The Current Comparator principle is applied to the measurement of ratio and dissipation factors of high voltage capacitors in a similar manner to the classical Schering Bridge but with greatly improved accuracy and resolution.

Guildline Instruments 99100A Capacitance Reference System provides for ratio calibration of Capacitance Measurement Systems. The 99100A System comprises a number of highly stable hermetically sealed capacitors with a switch array and a variable high voltage supply. The unique design allows the instrument to be used as a reference for ratio calibration of capacitance measurement instruments.