Direct measurement of AC current with coaxial current shunts down to 1 mA

The existing series of coaxial current shunts [1] has been expanded with a set of 6 coaxial current shunts of the same design for currents from 100 µA to 30 mA. Four of them have been implemented in AC current measurement with direct method and the operating range of AC current measurement has been expanded down to 100 µA. Additional validations of coaxial current shunts have been performed. According to new results the uncertainties for whole AC current range from 100 µA up to 20 A have been recalculated and in some points improved. The possibility of different design of coaxial current shunts for lower values has been considered.