Design of Fiber Optic F-P Cavity Pressure Sensor Based on Corrugated Diaphragm

摘要

To meet the need of the measurement in high temperature and high pressure in oil and gas well, an optical fiber extrinsic Fabry Perot(F-P) cavity pressure sensor based on corrugated diaphragm is developed. The measured medium is isolated from the fiber F-P cavity by corrugated diaphragm which can transmit pressure simultaneously. The probe of the sensor is fabricated by hydrogen and oxygen flame thermal bonding in high temperature technique, and the change of the senor's cavity length is compensated in temperature changing with cascading fiber bragg grating, and the sensor has characteristics of large dynamic range, high resolution, high repeatability, long term operation stability and high temperature resistance. The pressure measuring range is 0～69MPa, the repeatability is 0.01% FS, the hysteresis is less than 0.01% F S, the long term stability is less than 0.02MPa/y, and the sensor can satisfy the requirement of the measurement in the oil and gas well.