The Test equipment is in accordance with ASTM D 6208 in which an aluminium alloy is polarized at fixed current density for fixed time period in a solution of coolant & chloride solution. Upon polarization the maximum potential EB, or the break potential at which the passive aluminium oxide layer breaks down and subsequently minimum potential EG, or the protection potential at which oxide layer repassivates are recorded as the function of time intervals by Galvanostatic method. The software logs continuously the time and potential. These potential values are indications of the relative effectiveness of inhibitors to mitigate pitting corrosion of aluminium and its alloys. This method gives quick qualitative correlation of the measurements and susceptibility in service.