What is Partial Discharge ? get an answer with Doble’s EMI Surveyor.

What is Partial Discharge ? get an answer with the Doble’s EMI Surveyor.

Why the Partial Discharge Doble’s EMI Surveyor ?

  1. Doble’s EMI Surveyor is a diagnostics tool that is used in the detection of electrical defects in high voltage equipments.
  2. It works by measuring the electromagnetic energy (EMI) being released by partial discharge defects of high voltage equipments.
  3. Also, the electromagnetic energy could be due to arcing defects related to low or high voltage mechanical conductors. Using the EMI Surveyor, being a handheld device, allows assessments to be done with the HV equipment is in operation.
  4. This is advantageous because it allows for detection of areas that aren’t working properly for an in-depth offline inspection.
  5. That is, EMI measurements are made during the asset’s operation and when the asset is not working, the inspection is done.

For full analysis and diagnostic capabilities using the EMI Surveyor, additional kits are included for a comprehensive and detailed assessment. The additional kits are

  1. PDS200 spectrum analyser
  2. EMI sniffer
  3. Wireless synchronisation adapter
  4. Cables
  5. Antennae
  6. Split-core high frequency current transformer

What are the Features of the the Doble EMI Surveyor?

  • The EMI surveyor is a very user-friendly and portable handheld device.
  • It comes in a packaged kit which contains the accessories needed to perform a comprehensive and detailed EMI test.
  • The EMI Surveyor provides capabilities on both EMI and RFI spectrum of partial discharges.
  • Its flexibility allows for it to be connected to more than one sensor as part of its capability to be used in different applications.
  • The EMI Surveyor has the ability to allow the user listen to the radio noise brought about by a defect in a component.
  • Another of the EMI Surveyor’s versatility is that the signal waveform can be power cycle synchronised. This is done to enable phase resolved partial discharge analysis.

What are the Benefits of using the EMI Surveyor?

  • The EMI Surveyor offers the option to schedule outages so as to carry out needed maintenance and repairs.
  • It can be used to indentify up to 70 different mechanical and electrical defects in a high voltage electrical system.
  • Its application extends to finding insulation and conductor defects in other high voltage equipments such as swtichgears, cable termination, motors and generators.
  • It is a non-invasive tool used for electromagnetic (EMI) energy testing designed for use in power plants and rotating machines.
  • The high voltage connections present are not permanent, no arc flash hazard and operations of the plants are not interrupted or interfered with.
  • Reduction in costs and possibility of failure of electrical systems is an added benefit.

Which are the applications of Doble’s EMI Surveyor in testing processes performed include?

  • Fossil fuel plants
  • Hydroelectric plants
  • Refineries
  • Petrochemical sites
  • Steam turbine plants

With the EMI Surveyor, maintenance plans can be made in advance with respect to parts that need replacing.

This ensures that resources available can be channelled appropriately during periods of power outages and repairs done on the equipment.

How Performing tests with the EMI Surveyor?

  • Performing diagnostic tests with the EMI Surveyor is done using the included PDS200 kit.
  • The data obtained from the test is achieved via the split-core high frequency current transformer connected temporarily to the component being tested.
  • The EMI testing is done with measurements made via various radio frequencies for a full assessment.
  • That way, each frequency’s pattern is viewed and analysed such as gap discharges, corona, arcing and random noise.
  • The purpose of the EMI sniffer is to measure the electromagnetic energy emitted by the defected component or system.
  • This helps in the identification of and exact locating of the defect.




Detector Modes:          Peak, Average, Synchronous Peak and Average Mode (S.P.A.M.), Quasi-Peak, Synchronous Peak and Quasi Peak (S.P.Q.P.)

Sweep Processing:      Continuous, Counted and Single Mode


EMI                             RFI

Frequency Range                                50 kHz – 100 MHz                  50MHz -1000 MHz

Resolution Bandwidth (RBW)            9kHz / 120 kHz                       120 kHz / 6 MHz

Accuracy                                             ± 10 kHz                                 ± 100 kHz


External Supply           External DC adapter, 12V @ 2A

DC Adapter                 85-264 VAC (47-63 Hz) / 12 VDC

Internal Battery            Li-Ion, high capacity 7.2V, 6.6Ah

Battery Life                 >6 hours

Charging Time 3 hours


Enclosure                    IP64 – top covers closed

IP51 – top covers open

Transport case             IP67

Electrostatic discharge according to EN 61000-4-2

Humidity                     0-95% non-condensing

Temperature                Operating temperature:

-10°C to +50°C / 32°F-122°F

Storage temperature:

-20°C to +70°C / -4°F – 158°F

Comments (2)

  1. Emad R. Hammour November 17, 2017 Reply

    I have testing & commissioning team for distribution systems ( cables, C.B , ……)
    – now I need effective solutions to carry out acceptance testing for M.V cables ( 13,8 & 33 ) K.V ,,,,,
    – the owner put 50 G. Ohm ( ph- E )
    – the owner needs PD & TD ( off- line) – acceptance test for new cables …..
    – for me ….. I need one system ( VLF + PD + TD ) ….. if it is available on OMECRON, pls. Send your offer

    • Kaaraba Store December 3, 2017 Reply

      Hello Eng Emad,

      Are you looking for Portable Kit?

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