High-precision, miniaturized FBG gas flow sensor

Abstract

This paper designs and makes a high precision and miniature fiber Bragg grating (FBG) gas flow sensor for the low measurement accuracy and large volume of traditional electromagnetic flow sensor in complex working environment. The flow sensor is selected, and the high ratio diameter nozzle is used as the throttle element to produce the pressure difference on both sides of the nozzle. By pasting the FBG along the radial direction on the sensitive diaphragm, the deformation caused by the induction diaphragm due to the pressure difference, so as to associate the flow change with the FBG wavelength drift. The mathematical relationship between the measured gas flow and FBG wavelength values is derived from theoretical and simulation, and the dynamic flow characteristics of the flow sensor are obtained through experimental calibration. The experimental results show that the flow change and FBG wavelength drift, consistent with the theoretical analysis, the flow sensor dynamic flow measurement sensitivity is 11.04 NL/min. The FBG gas flow sensor designed in this paper has the advantages of high precision, miniaturization, strong anti-electromagnetic interference ability and easy integration in the complex working environment.