• Marija Čundeva-Blajer
  • Vladimir Dimčev
  • Mare Srbinovska
  • Genc Gjergjani
  • Dea Kuqi
  • Erind Dollaku


A b s t r a c t: According to ISO/IEC 17025 a laboratory shall have quality control procedures for monitoring
the validity of tests and calibrations undertaken, through participation in inter-laboratory comparisons (ILC) or profi-
ciency testing programmes (PT). This practice should be a periodic activity and in accordance with the international
standards. In the paper the results of the international ILC conducted by the Laboratory of Electrical Measurements
(LEM) of the Faculty of Engineering and Information Technologies at the Ss. Cyril and Methodius University in
Skopje, R. Macedonia (pilot laboratory), and the High Tech Test shpk – Tirana, R. Albania (HTT), both accredited
laboratories, will be presented. The ILC accomplished in the period March–April 2017 was conducted through cali-
bration of 61⁄2 digital multimeter Keysight 34401A for various electrical quantities. In the paper, the detailed meas-
urement procedure followed by the two laboratories as well as the evaluation and acceptance criteria will be given.
The results of the ILC will be presented and discussed. The ILC gives a significant contribution the quality and con-
fidence assurance in electrical quantities measurements at national and regional/international level.

Key words: inter-laboratory comparison; proficiency testing; calibrations; metrology of electrical quantities; quality assurance

[1] ISO/IEC 17025:2005. General Requirements for the Com­pe­ten­ce of Testing and Calibration Laboratories.
[2] ILAC-P9:06/2014 – ILAC Policy for Participation in Pro­ficiency Testing Activities.
[3] ISO/IEC 17043:2010. Conformity assessment – General require­ments for proficiency testing.
[4] Regulation on Requirements for participation on Pro­fi­ci­ency Test­ing. Inter-laboratory Comparisons and External Quality Assess­ment Programmes. IARM Procedure P06. Ver. 07. 2015.
[5] ЕА-4/18 TA: 2010 – Guidance on the level and frequen­cy of pro­ficiency testing participation.
[6] EA 03/04 G: 2001 – Use of Proficiency Testing as a Tool for Accre­ditation in Testing (with EUROLAB and EURACHEM). Reinstated according to EA Resolution 2012(29)24.
[7] EA INF 12: 2014 Benefits and importance of the partici­pation in EA highlighted PT schemes.
[8] EA-2/14 M: 2008 – Procedure for Regional Calibration ILCs in Support of the EA-MLA.
[9] EA Inter-Laboratory Comparisons (previous EAL-P7);
[10] ILAC Guidelines G8 on Reporting of Compliance with Specifi­cation.
[11] http://kcdb.bipm.org/ (last access 29.06.2017).
[12] Koepke, A.. Lafarge, T.. Possolo, A. and Toman, B.: Consensus building for interlaboratory studies. key comparisons. and meta-analysis. Metrologia. Volume 54, Number 3, p. 29 (2017).
[13] Kacker, R.. Datla,  R., Parr, A.: Combined result and asso­ciated uncertainty from interlaboratory evaluations based on the ISO Guide. Metrologia. Volume 39, Num­ber 3, pp. 279–294 (2002).
[14] Elster, C., Toman, B.: Analysis of key comparison data: critical as­sessment of elements of current practice with suggested impro­ve­ments. Metrologia. Volume 50, Num­ber 5, pp. 549–556 (2013).
[15] Arsov, L., Čundeva-Blajer, M.,  Sala, A., Hegedus, H., Malaric, R.: Interlaboratory Comparison of the Electrical Reference Standards of FEIT – Skopje and FER – Zagreb. 17th IMEKO TC4 Int. Symp.. Košice. Slovakia. 8–10 September 2010,  Paper No. 28, on CD ROM.
[16] Arsov, L., Sala, A., Čundeva-Blajer, M., Hegedus, H.: Inter­laboratory Comparison of DC Voltage Reference Standards.. Зборник на трудови на 9. Национална конференција со меѓународно учество ETAI 2009. Охрид, Р. Македонија, 26–29 септември 2009 (CD ROM E2–5).
[17] ISO 13528:2015. Statistical methods for use in proficien­cy testing by interlaboratory comparison
[18] Thompson, M., Ellison, S., Wood, R.: The International Harmo­ni­zed Protocol for the Proficiency Testing of Analytical Chemistry Laboratories, (IUPAC International Harmonized Protocol), Pure Appl. Chem.. Vol. 78, No. 1, pp. 145–196 (2006)
[19]Čundeva-Blajer, M., Dimčev, V., Srbinovska, M., Gergani, G., Kuqi, D., Dollaku, E.: Interlaboratory Comparison through Calibration of Calibration of 6½ Digital Multi­meter. Report on Interlaboratory Comparison. Faculty of Electrical Engineering and Imations Techynology – Skopje, and High Tech Tests HTT – Tirana. R. Albania, April 2017.

Jul 5, 2017
How to Cite
ČUNDEVA-BLAJER, Marija et al. QUALITY AND CONFIDENCE ASSURANCE IN ELECTRICAL QUANTITIES MEASUREMENTS – RESULTS OF FEIT–HTT INTER-LABORATORY COMPARISON. Journal of Electrical Engineering and Information Technologies - JEEIT, [S.l.], v. 2, n. 1, p. 15-23, july 2017. ISSN 2545-4269. Available at: <http://jeeit.feit.ukim.edu.mk/index.php/jeeit/article/view/56>. Date accessed: 24 apr. 2018.