Continuous, automatic and remote monitoring of corrosion

Abstract

The corrosion monitor system facilitates the detection and monitoring of material corrosion in remote areas. Sensors, which react to a corrosive environment similar to the material to be monitored, are placed in isolated areas and connected to a central control system via shielded cables. The system consists of a controller board, multiple dual preamp boards, a battery pack, sensors, and corresponding cables. The controller board consists of a microcontroller, memory, data conversion, and other control circuits. The dual preamp boards contain multiple precision instrumentation amplifiers, filtering, and voltage conversion circuits. The system operates on the principal that corrosion of a metallic conductor will cause a corresponding increase in the cross-sectional electrical resistance of that conductor. This change in resistance can be detected and monitored by passing a known constant current through the conductor and comparing the voltage across the conductor with that of a controlled reference conductor. The reference conductor is not exposed to the corrosive environment. As the sample conductor corrodes, small increases in the voltage across the element are measured with respect to the reference material. The resultant signals are multiplied and filtered to a detectable level and processed by the controller as data points stored in memory.