Low temperature characteristics of FBG with free arc shape for low temperature monitoring

Abstract It is important to monitor the iced condition for operating wind turbine blades. However, most sensors are difficult be used in this quite cold and lightweight environment. Although fiber bragg grating (FBG) a good candidate case. With change of temperature, thermal expansion coefficient thermo-optical coeffecient FBG material will affect accuracy characteristics sensor. Aiming at application optic sensor low temperature environment ultrathin requirement, with free arc shape package has been studied. The calibration experiments two packaged samples tested from -35°C ~20°C constant freezer alcohol tank. effects FBGs straight tubes compared. results show that can effectively reduce repeatability error improve its due providing possible contracting optical fibers. Flat makes it