A water corrosivity sensing system is currently under development that has the potential to combine the
strengths of rate measurement techniques such as linear polarization resistance with longer-term cumulative
damage measurements typically provided by electrical resistance probes. This sensor technology is applicable not
only to water pipeline systems, but a broad range of liquid and gas piping systems used in military facilities as
well as electric power, chemical, pulp and paper, and fossil fuel industries.
The current sensor embodiment operates on a diaphragm-based principle, where the diaphragm is a
sacrificial element that corrodes as the pipeline. Minute changes in diaphragm thickness can be detected by
monitoring the diaphragm response to applied pressure. Diaphragm response can be measured using several
techniques, including strain gage, optical gap, and capacitive methods. The current sensor embodiment described
in this paper uses a high-resolution optical approach to determine the effective diaphragm thickness loss. This
development effort will culminate with a field demonstration of the prototype sensing system installed in an Army
trial facility.