Radio frequency identification (RFID) based corrosion monitoring sensors Part 1 – Component selection and testing

Cost-effective radio frequency identification (RFID) transponders (tags) were investigated for use as wireless corrosion monitoring sensors. Performance metrics of read rate, received signal strength indicator, and minimum activation power were established for the as received tags. The effects of orientation, distance between transceiver (reader) and tag, and a metallic backing were evaluated using these performance metrics. Laboratory tests to determine the effect of a corrodible electromagnetic interference (EMI) shielding layer were conducted with a simple steel foil applied onto the surface of the plastic encased RFID tags. This layer acted as a barrier against the penetration of radio waves, preventing communication between the reader and tag. When the shielded RFID transponders were exposed to accelerated corrosion tests, the degradation of the shielding layer decreased the EMI shielding effectiveness and resulted in a strengthened communication between the reader and tag. The use of different thicknesses of this layer demonstrated the effect of cumulative corrosion damage. With appropriate calibration, the amount of corrosion could be estimated from the change in strength of communication between the reader and tag.