Passive Wireless Sensor for Atmospheric Corrosion Monitoring in Aerospace
Résumé
Corrosion leads to failures of systems and thereby to serious safety issues. It is consequently of first importance to monitor the corrosion process of structures via corrosion sensors. Electrical Resistance (ER) corrosion sensors are frequently used for that purpose. Despite the ability of such sensors to cover numerous domains of applications, they suffer from some critical points. Indeed, such sensors are energetically active which imply the presence of power supply, embedded electronic and/or cables in the structure under monitoring. These drawbacks limit the use of ER corrosion sensors, and globally active sensors, in extreme environment, such as for aerospace applications. In this context, there is a real interest in the design of fully passive wireless corrosion sensor, with a small size, able to be easily installed in aircraft critical points. In this study, a small, wireless and fully energetically passive corrosion sensor is presented. This zinc or aluminum wireless corrosion sensor gives indication of the corrosion state via a frequency shift and not an amplitude signal variation, which allow obtaining reliable data, not dependent of the transmission efficiency. This architecture is particularly pertinent to aerospace, due to the extreme variation of the environment. The obtained results on two metallic materials, displaying homogenous and localized corrosion, will be presented and the sensor answer, as function of the type corrosion will be discussed.