Geometrical effects in the current measurement by Rogowski sensor

Rogowski coil is made having no ferromagnetic material in a core. So the coil cannot be driven into saturation. This result in that Rogowski coils may be calibrated at relatively low currents, and used with confidence at very high currents. However the lowest level of current that can be measured is limited by the sensitivity of the voltage measuring instrument and system noise. Therefore, geometrical effects were investigated in order to measure high sensitivity of low level current and the significant source of error was examined as well. In the results, the sources of error were associated with coil designs, i.e. shape, uniformity and a geometrical location of current source inside and outside of the Rogowski coil.