Patent ID: 8634681
Filing Date: 2014-01-21
Classification: G01L,G02B

Abstract:
1. An apparatus for detecting changes in a pressure distribution along an extended fluid path, the apparatus comprising: an optical fibre cable for distributed pressure sensing, comprising: one or more optical fibres; and a buffer surrounding the one or more optical fibres and adapted to deform asymmetrically under isotropic pressure such that the fibre experiences asymmetric strain, which changes the birefringence of the one or more optical fibres in response to changes in the isotropic pressure; a light source arranged to launch optical pulses into the one or more optical fibres of the optical fibre cable; a detector for detecting light backscattered from within the one or more optical fibres of the optical fibre cable; and an analyser arranged to detect said changes in the pressure distribution along a length of the fibre cable from the detected backscattered light, wherein the detector comprises a polarisation detector arranged to detect polarisation states of the backscattered light.