Laboratory for testing and calibration is dedicated to bringing the highest quality and competent service to the clients according to JUS ISO IEC 17025:2001 standards requirements.
Laboratory for testing and calibration in Electrical engineering institute Nikola Tesla is accredited by the Association for laboratory accreditation of Serbia and Montenegro (Yuat). This means that we are certified to perform 114 different types of testing and calibrations.
Some of our Laboratory’s work specialties and the main areas of expertise are as follows:

• MEASUREMENTS AND TESTINGS OF GROUNDING SYSTEMS, LOW VOLTAGE ELECTRICAL INSTALLATIONS AND LIGHTNING PROTECTION SYSTEMS

• large grounding systems in electric power facilities: ground impedance, touch and step voltages, earth resistivity;
• low voltage electrical installations: earth loop impedance, insulation resistance, continuity;
• lightning protection systems: grounding resistance, equipotentiality.

• TESTING OF ELECTRICAL EQUIPMENT, APPLIANCES, MATERIALS AND PROTECTIVE DEVICES

• switchgears (dielectric and thermal characteristics)
• surge arresters (determination of the lightning impulse sparkover voltage test, power frequency sparkover voltage test, power frequency withstand test, AC and DC leakage current measurements, 5 kV insulation resistance test, a non-standard current impulse test, and finally the partial discharge voltage measurements
• low voltage and high voltage circuit breakers (thermal characteristics, power frequency voltage withstand test, lightning impulse voltage withstand test)
• electrical power cables and appliances (dielectric and thermal characteristics)
• protective equipment (insulation gloves and boots, insulation benches, voltage detectors, insulation sticks)

• THERMOGRAPHIC INSPECTION

• inspection of electrical equipment in power system installations at all voltage levels (detection and analysis of irregularities manifested through increased heating)
• stator core imperfection detection on power generators using rated induction method

• INSULATED OILS

• Physical characteristics (measurement of: density, kinematic viscosity, flash point, interfacial tension, refraction index)
• Chemical characteristics (measurement of: acid number, water content, inhibitor content, insulating oil chemical composition, dissolved gas analysis)
• Electrical characteristics (measurement of: dielectric dissipation factor, specific electrical resistivity, permittivity and breakdown voltage)

• ELECTRICAL INSULATION SYSTEM TESTING

• Rotating machines

• Off-line stator electrical insulation system and stator winding testing – Insulation resistance measurement, DC HiPot test, Capacitance and dissipation factor test, Off-line Partial discharge test, AC HiPot test, Stator Surge test, Winding resistance measurement etc.
• Off-line rotor electrical insulation system and winding testing - Insulation resistance measurement, Rotor RSO and Surge test etc.

• Power Transformers

• Power transformer preventive testing - Insulation resistance measurement, Capacitance and dissipation factor test, HV Bushing Insulation System testing, Leakage Inductance measurement, Turn ratio measurement, Winding resistance measurement etc.

• HV Current and Voltage transformers

• HV Current and Voltage preventive testing on site under EM interference - Insulation resistance measurement, Capacitance and dissipation factor test etc.


• CALIBRATION AND TESTING OF ELECTRICAL MEASURING INSTRUMENTS:

• DC voltage measuring instruments: digital and analogue voltmeters, DC voltage supplies, multifunction instruments (multimeters, calibrators), null indicators, accessories (voltage dividers, probes);
• DC current measuring instruments: digital and analogue ammeters, multifunction measuring instruments (multimeters, calibrators), accessories (shunts, dc current clamps), DC current suppliers;
• AC voltage measuring instruments: digital and analogue voltmeters, AC voltage supplies, multifunction instruments (multimeters, calibrators), null indicators, accessories (voltage dividers, probes);
• AC current measuring instruments: digital and analogue ammeters, multifunction measuring instruments (multimeters, calibrators), accessories (shunts, current clamps), AC current suppliers;
• Resistance measuring instruments: resistors, analogue and digital ohmmeters, analogue and digital conductor meters, resistance decades, resistance measuring bridges (according to Wheatstone and according to Thomson), multifunction instruments, insulation resistance test equipment, ground/earth resistance test equipment.

The implementation procedures of all the testing and calibration methods guarantee that the projects we deliver not only meet the safety standards and technical regulations, but are completed successfully and under the tightest schedules.
The main principles of laboratory for testing and calibration are:

1. following up and satisfying customers demands, existing regulations and standards
2. planning of all activities with continuous service improvement
3. constant improvement of tests methods and service quality
4. aggressive incorporation of innovative technologies into our practice so that our customer get assured that their projects are in the very best hands; data protection
5. continuous staff training and education stimulation
6. establishment of inter laboratory cooperation in order to verify our methods and gather broader knowledge