Aim tti aim instruments i prober 520 aim tti iprober 520 p the aim i prober 520 positional current probe is unlike any other current measurement device available the aim i prober 520 is the carol vorderman of the technical world it is slim good looking and very clever p p calibrated measurement of current normally requires the current to be passed through a closed magnetic loop typically this is done using some form of split clamp device whereas this is suitable for individual