| With the development of the society and improvement of industrialization,Optical FiberSensing Technique developed rapidly in recent years.Commercial products with simple structure,simple manufacturing process,high precision and being large-scale industrialized are needed.Generally the structure of traditional optical fiber pressure sensors is complicated.The manufacturing process is difficult to precisely control and production cost is high.These make them difficult for to be commercial product.In this paper,a plan of a new kind of fused compact EFPI fiber pressure sensor is presented.The sensor has some advantages such as long cavity length,simple structure,simple manufacturing process,convenience and flexibility in application comparing with traditional EFPI fiber sensor,while it can be used in the measurement of higher static pressure.The operation principle of EFPI fiber pressure sensor is analyzed and some experiments are completed.Different fabricating methods of EFPI fiber pressure sensors are compared and analyzed.Fused capillary based EFPI fiber pressure sensor is presented.Two pieces of flat single-mode fiber are fused to a piece of fused silica capillary whose length is about 1mm.The length of fused silica capillary is the length of initial Fabry-Perot cavity.Only fiber fusing and cleaving are needed in sensor fabrication processing.Demodulation algorithm of crossing correlation is used.Stress performance testing and temperature sensitivity test are done.Experiments have shown that the sensor has good stability and accuracy.At room temperature,in a range of 20 MPa,the pressure-cavity length sensitivity of the sensor is20.9nm/MPa,linearity is 0.9992.Measuring deviation is +/-0.16 MPa with continuous dynamic measurement in 3 hours.Cross-sensitivity of temperature-pressure is 0.034MPa/? during25?to 250?,which is for 0.17% of total range.Fused capillary based EFPI fiber pressure sensor will provide a foundation for mass-production of EFPI fiber pressure sensor. |
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