CALIBRATION OF INDUCTIVE VOLTAGE DIVIDERS AT EXTREMELY LOW-FREQUENCIES

A measuring system based on digital compensators is described. This ca n be used to calibrate inductive voltage dividers (IVDs) at extremely low frequencies. The division error at 1 Hz expressed relative to the complex division factor D at 32 Hz was found to be 1,9 x 10(-5) in mag nitude (uncertainty of measurement u(m) = 1,2 x 10(-6)) and -7,8 x 10( -5) rad in phase (u(p) = 6,5 x 10(-6) rad) for an IVD selected as an e xample. Additional characteristics such as the two-port parameters of the IVD can be measured by adding to the divider reference impedances in order to obtain a six-port network.