Multiplexers are used in PD measuring circuits when multiple measuring impedances are in use. This allows switching from the various measuring impedances to analyze the PD characteristics using only one PD detector. Examples of when multiplexers could be used are when testing bushings on 3-phase transformers or when PD testing 3 phases of power cables, simultaneously.
Datasheet:
MPX Features
Switching box for PD and synchronization voltage inputs from multiple measuring impedances
Only one cable required to PD detector for PD and voltage signal, respectively
Different models available with 4, 6, 8 or 12 channels
Switching of the active channel via rotary knob or remote controlled
Special versions for proprietary devices (such as Lemke brand) available including control cable
BNC input and output signal connectors
Robust metal housing with grounding rail
Built-in over-voltage protection