Fiber Bragg Grating Pressure Sensor Integrated with Epoxy Diaphragm

A fiber Bragg grating (FBG) sensor integrated with an epoxy diaphragm was developed for the measurement of pressure and water level. The bending strain of a circular diaphragm induced by uniform pressure was transferred to the FBG sensor. The response of the FBG sensor to the pressure was observed in terms of the Bragg wavelength shift which is linearly proportional to the strain. The effect of epoxy diaphragm thickness on the sensitivity and accuracy was investigated. The experimental results show that the sensitivity of FBG/epoxy diaphragm pressure sensor is decreasing with the increase of the diaphragm thickness. The sensitivities of the FBG pressure sensors with diaphragm thicknesses of 0.5 mm, 0.7 mm, and 1.0 mm were 175.5 pm/kPa, 89.5 pm/kPa, and 43.7 pm/kPa, respectively. The pressure measured by the proposed FBG sensor was compared with theoretical prediction and a close agreement was observed.

Automated summary

The fiber Bragg grating sensor integrated with an epoxy diaphragm is used for measuring pressure and water level. The thickness of the epoxy diaphragm affects the sensitivity and accuracy of the sensor, with a decrease in sensitivity as the diaphragm thickness increases. Experimental results show a close agreement between the pressure measured by the FBG sensor and theoretical predictions.