An embedded inductively coupled printed circuit board based corrosion potential sensor

In this work we demonstrate a printed circuit board based wireless inductively coupled corrosion potential sensor for monitoring steel reinforced concrete civil infrastructure. The sensor uses a coupled coil resonator whose resonant frequency varies due to the corrosion potential being applied across a varactor diode. The sensor is interrogated externally by an interrogator coil. An accelerated corrosion test was carried out on embedded sensor. The result shows that it can measure corrosion potentials with a resolution of less than 10 mV. The sensor is simple in design, inexpensive and passive making it battery less option for long-term corrosion monitoring, and widely deployable for civil structure.