Thin Fe-C Alloy Solid Film Based Fiber Optic Corrosion Sensor

In last few years, some transmitted type fiber optic corrosion sensors (FOCS) have emerged, but the fragile character makes them difficultly use in practice. In this paper, a novel thin Fe-C alloy solid film based fiber optic corrosion sensor has been developed. The sensing section is located at one end of the fiber. A double layer classic slab model has derived. According to the model, the change of reflectivity with time series relates to the corrosion location and corrosion rate of the sensing film. Two methods which are electroless plating deposition and DC magnetron sputtering have applied to prepare the nickel-phosphorus and copper reflective film, respectively. Electroplating and RF magnetron sputtering methods have been used to deposit Fe-C alloy sensing film. A sensing system has been setup to detect optical signal reflected from thin film. According to the change of the reflected light, the sensor can detect the corrosion when it generates at the sensor´s position