Skip to main content
Article
A novel capacitance sensor for fireside corrosion measurement
Review of Scientific Instruments
  • Heng Ban, Utah State University - Faculty Advisor
  • Zuoping Li
Document Type
Article
Publisher
AIP Publishing
Publication Date
1-1-2009
DOI
doi: http://dx.doi.org/10.1063/1.3262500
Abstract

Fireside corrosion in coal-fired power plants is a leading mechanism for boiler tube failures. Online monitoring of fireside corrosion can provide timely data to plant operators for mitigation implementation. This paper presents a novel sensor concept for measuring metal loss based on electrical capacitance. Laboratory-scale experiments demonstrated the feasibility of design, fabrication, and operation of the sensor. The fabrication of the prototype sensor involved sputtering deposition of a thin metal coating with varying thickness on a ceramic substrate. Corrosion metal loss resulted in a proportional decrease in electrical capacitance of the sensor. Laboratory experiments using a muffle furnace with an oxidation environment demonstrated that low carbon steel coatings on ceramic substrate survived cyclic temperatures over 500 °C. Measured corrosion rates of sputtered coating in air had an Arrhenius exponential dependence on temperature, with metal thickness loss ranging from 2.0 nm/h at 200°C to 2.0μm/h2.0 μm/h at 400°C. Uncertainty analysis indicated that the overall measurement uncertainty was within 4%. The experimental system showed high signal-to-noise ratio, and the sensor could measure submicrometer metal thickness changes. The laboratory experiments demonstrated that the sensor concept and measurement system are capable of short term, online monitoring of metal loss, indicating the potential for the sensor to be used for fireside corrosion monitoring and other metal loss measurement.

Comments

Publisher's version can be accessed at: http://aip.scitation.org/doi/10.1063/1.3262500

Citation Information
Heng Ban and Zuoping Li. "A novel capacitance sensor for fireside corrosion measurement" Review of Scientific Instruments Vol. 80 (2009)
Available at: http://works.bepress.com/heng-ban/44/