A seven-decade adjustable-ratio inductively-coupled voltage divider with 0.1 part per million accuracy

A step-up method for calibrating inductive voltage dividers up to 1 MHz

“…One method, well known in the literature for the error determination of IVD's, is the so-called "bootstrap" method [1], [2], [6] (Fig. 1).…”

“…The error evaluation is done by a computer program using (1). If the uncertainty of a single measurement is known we can calculate the uncertainty for each determination of the total error ex(D) using statistical methods.…”

Two-stage inductive voltage dividers

“…The admittances associated with the windings and also the very small magnetic couplings which, in practice, exist between the inductive components of the leakage impedances z x , z 2 , z 3 , z 4 and z 5 have been neglected. With the notation given, the mesh equations for the general case are given by Z,) -/ 2 Z I2 + / 3 Z, 4 For simplicity and clarity, consider initially the open-circuit case where / 3 = 0. It can then be shown that Examining eqn.…”

“…The divider winding around cores 1 and 2 was a 10-strand cable of the form previously described. 4 Core 1 comprised two low-loss highpermeability clock-spring cores 63 x 38 x 13 mm high and core 2 was a similar single core. The winding details are given in Table 1.…”

“…1 Introduction e 2 = 0 (4) The no-load primary-secondary errors of a voltage transformer which are due to the core-exciting currents creating voltage drops in the primary leakage impedances can be made acceptably small for most purposes by the use of low-loss high-permeability core materials and by careful attention to the winding design. For many exacting measurements, however, there is a need to reduce these errors to a considerably lower level than can be obtained by conventional means.…”