Abstract: An apparatus includes a detection element having a detection element property that changes when exposed to a corrosive substance, a testing device coupled to the detection element, the testing device configrued to measure the detection element property, and a processor in communication with the testing device, the processor configured to indicate the presence of the corrosive substance using the detection element property. In an embodiment, the detection element is metal and the detection element property is resistivity. In another embodiment, the apparatus further includes a comparison element coupled to the testing device and shielded from the corrosive substance, the comparison element having a comparison element property, and wherein the processor is configured to compare the detection element property to the comparison element property to determine whether the detection element property is within a predetermined range of the comparison element property.