The fiber Bragg grating temperature and pressure sensing system applied in oil pipeline

To improve the sensitivity of temperature sensor and pressure sensor so that they are applicable,the fiber Bragg grating(FBG) temperature sensor and FBG pressure sensor are encapsulated.The temperature sensitivity of the FBG temperature sensor is(0.052nm/℃) and the pressure sensitivity of the FBG pressure sensor is 0.8208nm/MPa from the experimental results.The temperature sensitivity and pressure sensitivity is 5.2 times and 273 times of that of bare FBG.The temperature and pressure response curve of FBG sensor is linear with reflective wavelength of FBG.After the FBG sensing system is used to detect the temperature and pressure of oil in pipeline about half month,the experimental results are consistent with those of electric sensor.The FBG sensing system can be used in pipeline on-line measurement.