Electrochemistry in remote places for assessing the corrosiveness in natural waters

• Corrosiveness of natural freshwater is complex and dynamic. • Its assessment is improvable with electrochemical corrosion data from in situ. • The design of a robust, mobile, autonomous probe and its verification are reported. • Data from various missions support the concept of bringing the lab to nature. The difficulties of estimating the corrosiveness of natural freshwater, particularly when microbial effects must also be taken into account, are briefly discussed. As a technological background, the specific needs of the hydropower industry are introduced, where the freedom in material selection appears more restricted than in other technologies. It is derived that gaining supplemental information on the corrosiveness of a particular natural water body by collecting electrochemical corrosion data on-site and in situ could be beneficial, provided the efforts are reasonable. As a proposed solution, the concept of an instrumented probe is introduced, a simple-to-handle device suitable for field application. Selected results are presented, which were obtained by such probes limited to acquiring corrosion potential data. Based on these data, the requirements for an upgrade of the device are derived. The design of the latest version of this device is presented in detail, including advanced electrochemical capabilities through potentiostatic functionality. The results gained from design verification and field tests are presented and support the feasibility of acquiring electrochemical corrosion data in situ as a basis for more accurately assessing the corrosiveness in complex environments, such as natural freshwater.