Reaction Engineering International (Murray, UT) will design, prototype, and demonstrate a miniaturized monitoring system, which can provide a real-time indication of tube surface conditions at key locations in a coal combustion boiler. The prototype system will be tested in pilot-scale combustion environments, and advanced profilometry techniques will validate accuracy of the resulting corrosion data. The project will culminate with a system-level demonstration of the miniaturized, self-regulating sensors at a full-scale pulverized-coal-fired plant.