Simultaneous measurement of pressure and temperature using dual-path distributed Brillouin sensor.

ABSTRACT

A sensing technique called a dual-path distributed Brillouin sensor (D-DBS) is proposed for simultaneous measurement of pressure and temperature. The D-DBS consists of a pair of sensing fibers, which are designed with different pressure and temperature coefficients of Brillouin frequency shift (BFS) by taking advantage of different fiber coatings. The highlight of this technique is to resolve the problem of the pressure-temperature cross sensitivity of the BFS within the optical fibers. The validation experiment shows satisfactory results, and it is indicated theoretically that the expected precisions of pressure and temperature are less than 0.25 MPa and 0.28°C, respectively.