The testing laboratory for energy meters is accredited by the Croatian Accreditation Agency based on the Croatian national law on accreditation (Narodne novine 158/03) according to the HRN EN ISO/IEC 17025 standard.
The accreditation certificate is valid for 5 years and it consists of testing static and electromechanical direct connected and transformer operated watt-hour meters of class indexes 1, 2, A, B, C, 0.2 S and 0.5 S for active energy and of class indexes 2 and 3 for reactive energy.
Tests of insulation properties:
- impulse voltage test
- AC voltage test
Limits of error due to influence quantities:
- variation of current
- voltage variation (230 V ± 10 % i +15 % / -20 %)
- frequency variation (50 Hz ± 2 %)
- ambient temperature variation
- reverse phase sequence and voltage unbalance (three phased meters)
- harmonic components, DC and even harmonics, odd and sub-harmonics of a 50 Hz reference frequency
Tests of electrical requirements
Tests of electromagnetic compatibility (EMC):
- fast transient burst test
- test of immunity to electrostatic discharges
- surge immunity test
- test of immunity to voltage dips and short interruptions
- test of immunity to power frequency magnetic fields of external origin and immunity to continuous magnetic fields of external origin
A list of the entire scope of accredited methods including a list of standards is given in the Accreditation Certificate.