Diaphragm FBG pressure sensor for high precision measurement in low pressure environments

To address the specific requirements for precision measurement of lithium battery barometric pressure under some special environments, a compact fiber-optic grating (FBG) sensor with small size, low pressure and high precision was designed and prepared in the present paper by means of principle analysis, theoretical modeling, simulation, and analog simulation. Its performance is tested through static calibration and dynamic experiments, and the results show that the sensor has a sensitivity of 4.31 pm/kPa and a precision of 0.4 %FS in the pressure range of 0-200 kPa, with an excellent linearity capable of reaching more than 0.9995, good linearity and reproducibility, and the ability to quickly monitor pressure changes. In addition, the sensor is able to withstand an acceleration of 6.5 g and the ability to withstand a vibration load of 2 g, within 2000 Hz. The study provides an important theoretical and application reference for the miniaturization and high precision of FBG diaphragm pressure sensors.