The potential transformer bridge with current comparator for measuring the voltage dependence of compressed-gas capacitors

In this paper, an alternative method for measuring the voltage dependent capacitance variation (VDCV) of compressed-gas capacitors is described. In the proposed method, the VDCV of the capacitor under test is measured by comparing it with a capacitor standard supplied with the secondary (low) voltage of a potential transformer. This transformer has its primary parallel connected with the capacitor under test. The paper presents and criticizes the test results obtained in which an uncertainty of at least 0.5 ppm is achieved.