We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

For the development of optical sensors, we investigate the advantages of employing an erbium doped fiber amplifier (EDFA) in a sensor system based on optical time domain reflectometry (OTDR). We first characterize the EDFA using the OTDR in terms of gain, insertion loss and pumping configurations. Then we compare the system performance with and without amplification. Our experimental results indicate that the use of the amplified OTDR system can increase the total reach of the sensor system.

Resumo Neste trabalho, apresentamos o resultado da caracterização do EDFA através do ganho utilizando técnica de reflectometria óptica. O resultado disto vai permite a determinação do ganho num sistema sensor amplificado à base de fibras ópticas, que também usa técnica de reflectometria para monitorar níveis de pressão, temperatura, corrosão e outros.