Testing and Calibration Laboratory

SONEL S.A. Testing and Calibration Laboratory offers verification and calibration certificates for the following instruments used for measuring the electrical parameters:

  • insulation resistance meters,
  • resistance meters,
  • fault lop meters,
  • meters of residual current device parameters,
  • low resistance meters,
  • Power Quality analyzers,
  • Portable Appliance Testers (PATs)
  • multifunctional meters with functional range covering the above-mentioned instruments,
  • voltmeters, ammeters (analogue and digital), multimeters, digital ammeters,
  • thermal imagers,
  • luxmeters,
  • pyrometers


Calibration certificate is a document which confirms the conformity of the manufacturer declared parameters with the national standard, with determination of measurement uncertainty.

According to the standard ISO 10012-1, Annex A, Sonel S.A recommends periodic application of metrological control for each instruments at least every 13 months.

Sonel S.A recommends metrological control (calibration) should preferably be within 13 months of using the equipment, but no later than 19 months from date of manufacture.

In the case of instruments used for the tests related to protection against electric shock, the person performing the measurements should be absolutely sure that his/her instrument is in good working order. The measurements made with a malfunctioning meter can contribute to an incorrect assessment of protection of human health or even life.

Useful information before sending the instruments for testing:

  • Lead time for meter testing is about seven working days from the instrument delivery day. The service lead time can be reduced on a case-by-case basis.
  • SONEL S.A. does not repair damaged instruments (this is the responsibility of the Service Dept which repairs only the instruments made by SONEL S.A.).
  • If the meter sent for tests is found to be defective and the user does not agree to the repair (only for meters made by SONEL S.A.), the user will be charged with the cost of fault diagnosing.
  • The instruments are tested for conformity with the parameters specified by the manufacturers which are listed, for example, in the operating manual. If the document with technical specification is not included, the instrument cannot be tested in the lab.
  • The party ordering the meter testing service should ensure a correct packing for transport, particularly if the meter is of the analogue type.