Simultaneous Measurement of Humidity and Temperature Based on an SiO2-Nanospheres Film Deposited on a Long-Period Grating In-Line With a Fiber Bragg Grating

• Autor(a) principal: Francisco Arregui
• Data de Publicação: 2011
• Outros Autores: José Luís Santos, Francisco Araújo, Ignacio Matias, Diana Viegas, Miguel Hernaez, Javier Goicoechea
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://repositorio.inesctec.pt/handle/123456789/1915

A novel configuration able to measure simultaneously relative humidity and temperature is proposed. The sensing head is based on a long-period fiber grating (LPG) coated with silica nanospheres in-line with a fiber Bragg grating. The polymeric overlay that changes its optical properties when exposed to different humidity levels is deposited onto the LPG using the electrostatic self-assembly technique (ESA), resulting into a humidity-induced shift of the resonance wavelength of the LPG. Considering the humidity range from 20% to 50% RH, a system resolution of 1.6% RH and 2.5 C was achieved. At higher humidity, from 50% to 80% RH, the corresponding resolution values were 2.4% RH and 0.4 C.