Simulated shunts as dc low-resistance travelling standards

We introduce a device that simulates a low-valued resistance standard (shunt) that can be employed as a metrology-grade travelling standard, for the traceability transfer of dc resistance in the low range, and in laboratory intercomparisons. The device is composed of a direct-current current comparator (DCCT) and a mid-range resistance standard. A prototype having a nominal resistance of 10m Ω has been constructed. Experiments show that it can be measured with high-accuracy commercial dc resistance bridges in their default operating configurations. The power coefficient is much lower than a corresponding shunt of the same nominal resistance. The expected long-term and transport stability is a few parts in 10⁶ or better.