Influence of Coating Material Properties on Temperature Measurement of Drawing-Tower Grating

The measurement accuracy of drawing-tower gratings (DTGs) has become the primary concern in many temperature monitoring applications because of its great advantages in building a large-capacity distributed fiber grating sensing network. The protective coating is a structural part of the DTG, and its unique response on temperature change will inevitably affect the DTG performance in temperature measurements. Several conventional organic coating materials are selected for temperature response experiments. We found that the material properties of DTG coatings (such as glass transition, hydrophilicity) have a significant impact on the temperature measurements of DTG. The glass transition of coating material causes the temperature response curve of DTG to be obviously bent, and causes the temperature-rise and -fall response curves to separate from each other. The hydrophilicity of coating material also causes the temperature-rise and -fall curves of DTG to separate significantly from each other.