Optical Fiber Relative Humidity Sensor Based on a FBG with a Di-Ureasil Coating

Sensors

Sandra F. H. Correia²  Paulo Antunes²  Edison Pecoraro³  Patrໜia P. Lima²  Humberto Varum¹  Luis D. Carlos²  Rute A. S. Ferreira² 

[1] Department of Civil Engineering, University of Aveiro, 3810-193 Aveiro, Portugal; E-Mail:;Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal; E-Mails:;Instituto de Telecomunicações, 3810-193 Aveiro, Portugal

关键词: fiber Bragg gratings;    optical fiber sensors;    relative humidity;    organo-silica hybrid;    structure health monitoring;   

DOI  :  10.3390/s120708847

来源: mdpi

【 摘 要 】

In this work we proposed a relative humidity (RH) sensor based on a Bragg grating written in an optical fiber, associated with a coating of organo-silica hybrid material prepared by the sol-gel method. The organo-silica-based coating has a strong adhesion to the optical fiber and its expansion is reversibly affected by the change in the RH values (15.0–95.0%) of the surrounding environment, allowing an increased sensitivity (22.2 pm/%RH) and durability due to the presence of a siliceous-based inorganic component. The developed sensor was tested in a real structure health monitoring essay, in which the RH inside two concrete blocks with different porosity values was measured over 1 year. The results demonstrated the potential of the proposed optical sensor in the monitoring of civil engineering structures.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.