A RFID Sensor for Corrosion Monitoring in Concrete

A radio frequency identification (RFID) sensor for corrosion monitoring in concrete is presented. The sensor can perform linear polarization, open circuit potential, and temperature measurements. The sensor obtains its power from an external RFID reader, which also functions as a datalogger. The sensor's electronic circuit comprises an RFID modem, a low-power microcontroller, and a three-electrode low-power potentionstat. The electronic circuit and the three electrodes are housed in a 3D-printed case measuring 11.8 cm × 4 cm × 5.6 cm. An analysis of the inductive coupling between the reader's and the sensor's antennas is carried out to guide the optimization of the RFID communication link. Tests with a wet and a concrete electrochemical corrosion cells show that the developed sensor has a performance comparable with costly and bulkier benchtop potentiostats. An accelerated corrosion test was conducted by embedding the electrodes in concrete for 24 days. Linear polarization resistance measurements obtained from the developed sensor show the initiation and progression of corrosion. An uncertainty evaluation is carried out showing that the developed RFID sensor has an accuracy compatible with precision benchtop instruments.