The AQS 9110a series of quadripole (measuring impedance) is a fully passive measurement system optimized for use with the DDX series of partial discharge detectors.
It is designed for simultaneous measurement of high-frequency discharge pulses as well as the HV test voltage.
The AQS 9110a is equipped with a user selectable three positions internal voltage divider and it is retro-compatible with Haefely older DDX series as e.g. DDX 9101 or DDX 7000/8003 (requires max. 7 Vac voltage signal output).

Advantages
• No batteries or charger needed.
• Multi coupling capacitor ready.
• High coupling capacitors’ capacitance range.
• The built-in overvoltage protection will protect the PD detector in case a flash in the test object would happen during the test.

Applications
• Power and distribution transformers
• Instrument transformers
• Rotating machines
• Switchgears (MV/HV/GIS)
• Surge arresters
• Bushings
• Cables
• Power capacitors
• Components testing
• Research and development