Research On Corrugated Diaphragm Fabry-Perot Pressure Sensor

The optical fiber pressure sensors have many advantages such as radiation-resisitant, immunity to electromagnetic interference, high sensitivity, high accuracy, easy to form sensor network etc. It may have a good prospect in engineering construction, petrochemical industry or large substation equipment, some application domains with high radiation, electromagnetic interference, temperature or other extreme harsh environments. Industrial safety and national defense require a mass of micro sensors which have the characteristics of multifunction, high sensitivity and batch production. The corrugated diaphragm type pressure sensor we studied is an improvement of the present Fabry-Perot interferometric pressure sensor.We designed and developed a method of corrugated diaphragm type Fabry-Perot pressure sensor. In detail the structure of the sensor design and production. Using corrosion-resistant and high temperature resistant material of 316L stainless steel as the corrugated membrane and flange preparation, effectively reduces the thermal stress due to thermal expansion coefficient mismatch. Using Coventor Ware simulation software for corrugated diaphragm has carried on the simulation of the mechanical structure and the structural parameters optimization. In the design of the sensor used properly, the optical fiber flange ensures parallel to the optical fiber end face and the sensitive membrane, thus forming a high quality Fabry-Perot cavity interference method. The structure also is helpful for the initial cavity long stability, reduced the sensor error.Experimental demodulation system is established, with the method of phase demodulation based on Fourier transform sensors, to test the pressure characteristics in detail. Experimental results demonstrate that in 0?0.1 MPa pressure range, the sensor has good repeatability and stability, the hysteresis error is 1.46%, the linearity fitting is 99.61%, the sensitivity reached 1.08?m/KPa, and the sensor resolution is 0.000001 MPa.Temperature sensitivity test of corrugated diaphragm type Fabry-Perot pressure sensor is studied, and analyze the causes of temperature sensitive sensor. The temperature from 0 to 60?, the sensor is made of epoxy resin in the cavity length change of 4.971 ?m, temperature sensitivity is 0.083?m/?, Temperature drift is 8.543×10-4.