At each measurement location, the emission from the impulse generator was measured using a D-dot probe and a B-dot probe but the 6 B / 61 and bD/bi signals were not recorded simultaneously. The D-dot probe and its built—in balun together had a sensitivity of 4.425 mV per (V/in)/ns. The B-dot probe and its built-in balun together had a sensitivity of 6.25 mV per (A/in)/ps. At each probe position, a minimum of three measurements were made for each of the three possible probe orientations. Shot to shot variations were not significant and magnitude variations of the observed signals on the digitizing oscilloscope were within 109r. The output of the probes were connected to a Hewlett Packard DSO Model HP54502A, which has a digitizing rate of 400 Msa/s, through a 0. 1 in length of ethernet cable. The digitized signals were downloaded onto a disk through a HPIB interface for subsequent processing.