Octofilar resistors with calculable frequency dependence
J Boh cek, Barry Wood · Metrologia · 2001
The results are presented of calculation of the frequency dependence of an octofilar resistor, the resistive element of which is folded in such a way that it forms four long loops connected in series. Magnetic fluxes produced by the loops tend to cancel, similar to the fluxes produced by the two loops of the common quadrifilar reversed resistor. The folded length of the octofilar resistive element is one half of that of a quadrifilar resistor made from the same wire and having the same nominal resistance, and the octofilar resistor has a smaller frequency dependence. As an example, a 12906 Ω octofilar resistor is described, for which the frequency dependence of its parallel equivalent resistance is more than seven times smaller than that of a previously made 12906 Ω quadrifilar resistor in the frequency range 500 Hz to 5 kHz.