A fuel dispensing system comprising a fuel tank adapted to contain a quantity of fuel. A fuel dispenser is in fluid communication with the fuel tank via piping. A pump operative to transfer fuel from the fuel tank to the fuel dispenser is also provided. The fuel dispensing system further comprises a corrosion detection assembly operative to identify presence of a corrosive substance in the fuel. The corrosion detection assembly includes at least one corrosion sensor positioned to be in contact with fuel vapor in the fuel dispensing system, the corrosion sensor producing a detector signal indicating presence of the corrosive substance. The corrosion sensor according to this aspect has a printed circuit multilayer structure in which at least one sensing element is positioned on an exposed surface of the multilayer structure and at least one reference element is positioned on an inner surface of the multilayer structure to be unexposed to the fuel vapor. Electronics in electrical communication with the corrosion sensor are operative to interpret the detector signal and produce an output if the corrosive substance is present.