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Amplified OTDR systems for multipoint corrosion monitoring.

Nascimento JF, Silva MJ, Coêlho IJ, Cipriano E, Martins-Filho JF - Sensors (Basel) (2012)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Polytechnic School of Pernambuco, University of Pernambuco (UPE), Recife, PE, Brazil. jehanfonseca@hotmail.com

ABSTRACT
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.

No MeSH data available.


OTDR traces of the amplified (solid line) and non-amplified (dashed line) multipoint sensor system for OTDR pulsewidth of (a) 10 ns and (b) 50 ns. Pump power at EDF input is 17 mW.
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f2-sensors-12-03438: OTDR traces of the amplified (solid line) and non-amplified (dashed line) multipoint sensor system for OTDR pulsewidth of (a) 10 ns and (b) 50 ns. Pump power at EDF input is 17 mW.

Mentions: In Figure 2 we present the OTDR traces obtained from the experimental apparatus shown in Figure 1(a) (dashed line) and Figure 1(b) (solid line) for 10 ns and 50 ns OTDR pulsewidths. In the left hand side graphs one can see six peaks corresponding to the first six sensor heads of the systems, whereas the right hand side graphs show the remaining eight sensor heads, numbered as in Figure 1. Additional peaks can be seen, which are due to reflections in the interface between different fibers or due to the optical attenuator inserted in the system. Note that the first six sensor heads are not amplified, therefore they only experience attenuation due to the bandpass filter in the amplified system (Figure 1(b)). This explains why they present lower intensity OTDR traces in the amplified scheme than in the non-amplified scheme. On the other hand, the opposite behavior can be observed in the last eight sensor heads, i.e., the amplified scheme presents higher intensity OTDR traces, since the sensor heads experience the EDFA gain.


Amplified OTDR systems for multipoint corrosion monitoring.

Nascimento JF, Silva MJ, Coêlho IJ, Cipriano E, Martins-Filho JF - Sensors (Basel) (2012)

OTDR traces of the amplified (solid line) and non-amplified (dashed line) multipoint sensor system for OTDR pulsewidth of (a) 10 ns and (b) 50 ns. Pump power at EDF input is 17 mW.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376602&req=5

f2-sensors-12-03438: OTDR traces of the amplified (solid line) and non-amplified (dashed line) multipoint sensor system for OTDR pulsewidth of (a) 10 ns and (b) 50 ns. Pump power at EDF input is 17 mW.
Mentions: In Figure 2 we present the OTDR traces obtained from the experimental apparatus shown in Figure 1(a) (dashed line) and Figure 1(b) (solid line) for 10 ns and 50 ns OTDR pulsewidths. In the left hand side graphs one can see six peaks corresponding to the first six sensor heads of the systems, whereas the right hand side graphs show the remaining eight sensor heads, numbered as in Figure 1. Additional peaks can be seen, which are due to reflections in the interface between different fibers or due to the optical attenuator inserted in the system. Note that the first six sensor heads are not amplified, therefore they only experience attenuation due to the bandpass filter in the amplified system (Figure 1(b)). This explains why they present lower intensity OTDR traces in the amplified scheme than in the non-amplified scheme. On the other hand, the opposite behavior can be observed in the last eight sensor heads, i.e., the amplified scheme presents higher intensity OTDR traces, since the sensor heads experience the EDFA gain.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Polytechnic School of Pernambuco, University of Pernambuco (UPE), Recife, PE, Brazil. jehanfonseca@hotmail.com

ABSTRACT
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.

No MeSH data available.