A system to mesure 8/20 μs (front time/time to half value) impulse currents from 5 kA to 50 kA (peak value) has been developed at LNE. The system relies on the use of non-invasif wideband (maximum 4 MHz) current sensors, of a 12 bits digitiser with a maximum sample rate of 100 Mega-samples per second and of a data acquisition and treatement software. The values of the expanded uncertainties (k = 2) are 1.4 mA·A−1 for the peak value and 15 ns·μs−1 for impulse current time parameters.

Key words

impulse current
8/20 μs wave
wideband current sensor
rogowski coil
uncertainty budget