In October 2024 we reached the milestone of
10 years in business !

High Frequency Diagnostics & Engineering (HFDE) Ltd provides testing and consulting services for all aspects of Partial Discharge (PD):

  • PD surveys of MV / HV / EHV plant, substations, wind farms, etc.
  • Permanent or short-term PD monitoring of power transformers, GIS, cables, switchgear
  • Insulation diagnostics, consultancy, risk assessment
  • Design and implementation of high voltage PD test facilities
  • PD testing of small / medium sized components
  • Customised training courses (PD awareness, detection principles, diagnosis, best practice)
  • Design, prototyping and optimisation of PD sensors
  • Calibration services for UHF PD sensors

Please see our Services Leaflet.

On-site PD Investigations:

HFDE's R&D Lab / Workshop:

Our UHF PD Sensor Development and Test Facility:

Specialist Monitoring and PD Location Services:


HFDE’s founder, Dr Martin Judd, is a Chartered Electrical & Electronic Engineer with 40 years’ experience. Previously, he was Professor of High Voltage Technologies at the University of Strathclyde in Glasgow, where he carried out pioneering R&D on PD for 20 years and served as manager of the HV Laboratory.