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  • Sharmistha Bhadra
  • Gregory Bridges
  • Douglas Thomson



Project TitleWireless passive corrosion sensor
Track Code80.02.0764
Short Description

A new type of passive wireless sensor capable of detecting the corrosion of reinforcing steel.


Corrosion of reinforcing steel, which results in premature deterioration of reinforced concrete structures, is a worldwide problem. Most corrosion sensing techniques require some type of wired connection between the sensor and monitoring electronics. This causes significant problems in their installation and long-term use. Researchers at the University of Manitoba have developed a new type of passive embeddable wireless sensor that is based on an LC coil resonator where the resonant frequency is changed by the corrosion potential of the reinforcing steel. The resonant frequency can be monitored remotely by an interrogator coil inductively coupled to the sensor coil. The sensor unit comprises an inductive coil connected in parallel with a voltage dependent capacitor (varactor) and a pair of corrosion electrodes consisting of a reinforcing steel sensing electrode and a stainless steel reference electrode. Change of potential difference between the electrodes due to variation of the corrosion potential of the reinforcing steel changes the capacitance of the varactor and shifts the resonant frequency of the sensor. A time-domain gating method was used for the interrogation of the inductively coupled corrosion sensor. Results of an accelerated corrosion test using the sensor indicate that the corrosion potential can be monitored with a resolution of less than 10 mV. The sensor is simple in design and requires no power source, making it an inexpensive option for long-term remote monitoring of the corrosion state of reinforcing steel.

Tagsengineering, chemistry
Posted DateJun 14, 2016 3:03 PM


Sharmistha Bhadra
Gregory Bridges
Douglas Thomson


Robert Werbowesky

One page summary


Robert Werbowsky

Technology Manager

Ph: +1(204)474.7865



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Technology Transfer Office
631 Drake Centre, 181 Freedman Crescent,
University of Manitoba, Winnipeg, MB R3T 5V4 Canada
Office: 204.474.6200  Fax: 204.261-3475