Interlaboratory Comparisons of Calibration Results of the Measures of Electrical Resistance of Direct Current

For the accredited calibration laboratories in Ukraine, a second round of inter-laboratory comparisons (ILC) of the results of calibration of electrical resistance measures of direct current was conduc­ted. It is important to conduct such rounds of ILC of results with the involvement of an increasing number of calibration laboratories. This will, accordingly, establish the competence of an increasing number of calibration laboratories, which is quite relevant today. The article presents the results of the first round of ILC of the measures of electric resistance 1 Ohm, 10 Ohm and 100 Ohm on a direct current. As an comparison examples by reference laboratory measurement of electrical resistance of direct current P321 and P331, which were already used in the first round of ILC, were selected. The reference labo­ratory has research the measures of electrical resistance as a means of comparison, defined the reference values of comparison with the calculation of their extended uncertainties according to the mea­surement model. The comparison of the results of measurements obtained during the calibration of the measures of electrical resistance of eight laboratories took place according to the radial scheme from 2018 to 2019. The deviations of the results obtained by each laboratory were determined and their correctness was evaluated taking into account the uncertainty of measurements by one of the criteria for performance statistics for the selected electrical resistance ra­tings. The obtained En values show that for all laboratories participating satisfy the set criterion, except for the result of one laboratory for electrical resistance of 10 Ohms. A comparative analysis of the results of the calibration of resistance measures for laboratories that took part in the first and second rounds was carried out.