This type of sensor is used to assess corrosion in high-humidity atmospheres, salt-spray environments, or areas of high humidity beneath low-temperature insulation. It
consists of two dissimilar metals that are electrically insulated from each other.
Condensation and rainfall can bridge the gap between the substrate layer and the conductive layer. When a conductive path forms, an electric current is generated due to the
potential difference between the two metals, leading to corrosion of the substrate. This corrosion current can be measured and analyzed, allowing for a quantitative
assessment of the corrosivity of the installation environment. Because the distance between the two metals is very small, a water film forms easily under conditions of high
humidity or condensation. Corrosion occurs not only in liquid solutions but also in atmospheric environments; the sensor effectively simulates the condensation caused by
physical phenomena in high-humidity conditions, which can otherwise lead to corrosion issues.