<title>Fiber optic grating moisture and humidity sensors</title>

Polymer-coated fiber Bragg grating for relative humidity sensing

“…This effect could, therefore, be used to establish the relationship between the filter characteristics and the humidity level. Recent work by Laylor et al [19] presented some promising results, but data on the composition of the coating(s) used were not given, neither were the coating thickness nor the response 1530-437X/$20.00 © 2005 IEEE time of the probe under circumstances other than for one specific test in soil. The work of several Swiss researchers has been discussed in recent two papers [20], [21] and the results obtained from a preliminary investigation herein are presented and cross compared with data extracted from the literature, as considered later.…”

“…In this paper, the use of a FBG together with a moisture sensitive polymer coating is implemented for humidity sensing, taking note of previous recent work using the Bragg grating concept and developing further from it [19]- [21]. The sensing principle is also based on the strain effect induced in the FBG through the swelling of the polymer coating caused by the absorption of the moisture.…”

Characterisation of a polymer-coated fibre Bragg grating sensor for relative humidity sensing

“…This concept has since been discussed by several authors [9][10][11], with intended applications in various areas. The sensing principle used in this work is based on the strain effect induced on the FBG through the swelling of the moisture sensitive polymer-coated on the device and builds upon previous preliminary research published by the authors [12].…”

A suite of optical fibre-based chemical sensors for environmental monitoring

“…The influence of humidity on a polymer-coated FBG was first reported by Giaccarri et al [1] and the technique described for humidity detection has been further explored by several research groups [2] [3] including those at City University London.…”