The 9910A HIGH VOLTAGE Capacitance Bridge is an instrument employing the AC Current Comparator principle. The 9910A is a versatile instrument for a wide range of applications including capacitance measurements, cable testing, corona loss measurements, insulator and dielectric testing, inductance measurements, potential transformer error measurements, shunt reactor loss measurements and power transformer testing.

The model 99100A Capacitor Reference 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 in addition to being used reference capacitors. Provision is made for an additional external reference capacitor and also for additional extension of the switched array range with another bank of reference capacitors.