On-line PD Testing and Monitoring of HV/EHV GIS

Partial Discharges can occur at various points in gas insulated switchgear. Sources of PD include protrusions on conductors, floating particles and delamination or voids at barrier insulators. By PD testing and monitoring, the development of underlying defects can be detected and insulation condition assessed.



  • UHF Barrier sensors attached over uncovered insulation barriers.
  • UHF Window sensors attached over viewports and inspection windows.
  • UHF Couplers built-in to the GIS.


Test Equipment






Monitoring Systems






Test Services

  • Comprehensive range of test services for on-line and off-line condition assessment.
  • Reactivation services offered to ensure the safe energisation of inactive HV assets.






Contact us

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