Sub-Hz Frequency Dependence of New 1 Ω Standard Resistors Based on Nickel-Chromium Alloy Metal Foil Technology

When considering the dc resistance of 1 Ω standard resistors, frequency-dependent phenomena below 1 Hz down to a few mHz can noticeably reduce the comparability of results. This issue has been identified in the context of international comparisons between National Metrology Institutes. Recently, a new type of metal-foil 1 Ω resistors became available. Collaborative low frequency measurements involving NMIJ, PTB and BIPM showed the excellence of these resistors and the influence of cabling on this measurement.