Use of RLC comparator for measurements of elements of national standard of capacitance unit

W artykule przedstawiono wykorzystanie komparatora RLC w badaniu elementów państwowego wzorca jednostki miary pojemności elektrycznej i jego wzorców odniesienia. Badania przy pomocy komparatora dokonano trzema metodami: metodą bezpośredniego porównania, podstawienia i przestawienia wzorców miejscami. Otrzymane wyniki pokazują, że zastosowanie komparatora RLC do pomiarów wzorców pojemności pozwala na wyznaczenie ich wartości z niższą niepewnością pomiaru w porównaniu ze stosowanymi dotychczas mostkami transforma-torowymi.The paper presents the use of a comparator RLC for measurements of elements of the national standard of capacitance unit which consists of four 10 pF capacitors of type 11A. The measurements of the national standard were made using transformer bridges: AH 2500A and GR 1621. To calculate the real values of each capacitor the group method was used. The relative combined standard uncertainty for the group method is equal to 0,5 žF/F. The reference standards for the national standard of capacitance units are: capacitor 100 pF of type 11A, capacitors 10 pF and 100 pF of type 1408 and capacitors 10 pF, 100 pF and 1000 pF of type 1404. The measurements of elements of the national standard of capacitance unit by means of the RLC comparator are made using three methods: direct comparison, substitution and replacing of standards. The results obtained show that the use of the comparator RLC for measuring the standards of capacitance allows determining their value with a lower measurement uncertainty compared with the previously used transformer bridges. The relative combined standard uncertainty of the capacitors 10 pF of type 11A is less than 0,2 ×10-6 and of the reference standards is less than 3 ×10-6 for the measurement methods using the RLC comparator