Speed Sensor Study Using A Single Fiber Bragg Grating (FBG)

Optical Fiber Sensors (OFS) based on Fiber Bragg Grating (FBG) technology possess several advantages such as sensitivity, reliability, low intrusively, galvanic insulation, as well as the ability to provide quasi-distributed remote measurements. FBGs are extensively employed in optical sensing and can compete favourably with traditional electrical strain gauges. In this research, speed sensor using a single Fiber Bragg Grating has been studied. The study was conducted using an Optical Spectrum Analyzer (OSA) and a 1300nm Super Luminescent Diode (SLD). The experiment resulted in the bending of the FBG. In this experiment, the FBG was located inside a wind tunnel. An increasing bending of the FBG was noticed as the speed and pressure in the tunnel increased from 7.22 to 27.25 m/s and 31.90 to 450.80 Pa respectively. The Bragg wavelength shift also increased with speed and pressure. The measured sensitivities were 0.0058nm/ms-1 for speed and 0.0463 ms-1/Pa for wind pressure. The sensitivity measurements are very important especially when FBG is to be applied as a sensing system. As such, the FBG in question can be used as a strain sensor, wind pressure sensor and wind speed sensor.