Abstract: The invention concerns corrosion sensors comprising a resistor, a voltage meter for determining voltage output across said resistor; and at least three different layers, each layer comprising a different material, said layers comprising: (a) non-corrosive conducting layer; (b) metal layer; and (c) electrically insulating layer deposed between the conducting layer and the metal layer; wherein the resistor connects the conducting layer and the metal layer. The invention further concerns use of such sensors use in monitoring and trouble-shooting corrosion impacts.