A high-sensitivity fiber Bragg grating(FBG) pressure sensor is proposed,which is sealed with the daul bellows.And the sensing mechanism of the proposed sensor is theoretically analyzed.The experimental results show that the pressure range is 0～1.2 kPa,the sensitivity is 688.2 pm/kPa,the linearity-fitted is 0.9973.So it can be used as the liquid ometer with high-precision. 更多还原