Bandwidth modulation and centre wavelength shift of a single FBG for simultaneous water level and temperature sensing

• Main Authors: Vorathin, E., Z. M., Hafizi
• Format: Article
• Language: English
• Published: Elsevier Ltd 2020
• Subjects: TS Manufactures
• Online Access: http://umpir.ump.edu.my/id/eprint/28446/1/Bandwidth%20modulation%20and%20centre%20wavelength1.pdf; http://umpir.ump.edu.my/id/eprint/28446/; https://doi.org/10.1016/j.measurement.2020.107955; https://doi.org/10.1016/j.measurement.2020.107955

A diaphragm-based hydrostatic level transducer with the use of a single Fibre Bragg grating (FBG) is presented for simultaneous measurement of water level and temperature. In order to distinguish the mismatch between water level and temperature sensitivity, a bandwidth modulation and centre wavelength shift measurement technique was introduced. The change in bandwidth is sensitive towards water level variations with a sensitivity of 0.0015 nm/cm. Meanwhile, the change of centre wavelength is sensitive towards water level and temperature variations, with sensitivities of 0.0008 nm/cm and 0.0365 nm/°C, respectively. By expressing the obtained sensitivities in a matrix equation approach, simultaneous water level and temperature measurement can be predicted accurately.