Design And Research Of Intensity Modulation Fiber Optic Pressure Sensor

Pressure monitoring in harsh environments has been more and more widely used in oil and gas field exploitation,aerospace,power,chemical,coal and other industries.Compared with traditional electrical sensors,optical fiber pressure sensors have many advantages,such as good electrical insulation,resistance to electromagnetic interference,light weight,high resolution and small size,high temperature and humidity resistance,and show great potential in the field of pressure measurement.This article aims to design a low-cost,mass-producible,portable fiber optic pressure sensor with a higher demodulation rate using a relatively simple demodulation process.The main content of the paper includes:(1)Based on the research of optical fiber exiting light field,a theoretical model of pressure sensor light emphasis system is established.The effect of fiber probe parameters on sensor sensitivity is analyzed by numerical simulation method.The mechanical analysis and multiphysics simulation of the sensor pressure sensitive unit are carried out.(2)MEMS processing of intensity-modulated optical fiber pressure sensor.It mainly includes three parts: sensor pressure sensitive device manufacturing,optical fiber integration and sensor packaging manufacturing.The production of sensor pressure sensitive devices mainly includes pressure sensitive diaphragm and high borosilicate glass base.According to the sensor dimensions,the sensor packaging structure is designed and processed.(3)The sensor pressure demodulation system is established;the temperature-pressure test platform is established.At different temperatures,the static pressure test of the sensor was analyzed.Use the sinusoidal pressure test platform to perform dynamic pressure test on the sensor at room temperature.The results show that the sensor has a linear sensitivity of about 139 mv / MPa in the pressure range up to 1MPa at room temperature.After three reproducible experiments,the repeatability error and nonlinear error are about 2.15% and less than 2.51%,respectively.The temperature coefficient of the sensor is approximately 0.87 mV / ? in the range of 20 ? to 150 ?.The sensor was initially tested in the environment of 1kHz high frequency dynamic pressure range.Using MEMS technology,sensors can be mass produced,thereby reducing costs.