{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T21:13:31Z","timestamp":1777670011010,"version":"3.51.4"},"reference-count":47,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2012,6,27]],"date-time":"2012-06-27T00:00:00Z","timestamp":1340755200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>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\u201395.0%) 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.<\/jats:p>","DOI":"10.3390\/s120708847","type":"journal-article","created":{"date-parts":[[2012,6,28]],"date-time":"2012-06-28T11:17:49Z","timestamp":1340882269000},"page":"8847-8860","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":109,"title":["Optical Fiber Relative Humidity Sensor Based on a FBG with a Di-Ureasil Coating"],"prefix":"10.3390","volume":"12","author":[{"given":"Sandra F. H.","family":"Correia","sequence":"first","affiliation":[{"name":"Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"CICECO, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9129-3539","authenticated-orcid":false,"given":"Paulo","family":"Antunes","sequence":"additional","affiliation":[{"name":"Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"Instituto de Telecomunica\u00e7\u00f5es, 3810-193 Aveiro, Portugal"}]},{"given":"Edison","family":"Pecoraro","sequence":"additional","affiliation":[{"name":"Instituto de Telecomunica\u00e7\u00f5es, 3810-193 Aveiro, Portugal"},{"name":"Instituto de Qu\u00edmica, Universidade Estadual Paulista, Araraquara 14800-900, SP, Brazil"}]},{"given":"Patr\u00edcia P.","family":"Lima","sequence":"additional","affiliation":[{"name":"Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"CICECO, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Humberto","family":"Varum","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4747-6535","authenticated-orcid":false,"given":"Luis D.","family":"Carlos","sequence":"additional","affiliation":[{"name":"Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"CICECO, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Rute A. S.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"CICECO, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Paulo S.","family":"Andr\u00e9","sequence":"additional","affiliation":[{"name":"Physics Department, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"Instituto de Telecomunica\u00e7\u00f5es, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2012,6,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1016\/j.sna.2008.01.017","article-title":"Fibre-optic sensor technologies for humidity and moisture measurement","volume":"144","author":"Yeo","year":"2008","journal-title":"Sens. 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