a system for detecting and measuring corrosive reaction of metals in an environment . the system includes : a remotely placeable sensor head containing a galvanic couple made of metals identical to those involved in the corrosion problem , with the couple coiled in the shape of a sprial ; and , operatively associated electronic circuitry to amplify , integrate , and store in a non - volatile memory , e . g ., a bubble type memory , for future recall the amount of galvanic current that is flowing and that has flowed when corrosion is , or has been , occurring .