Patent ID: 9459164
Filing Date: 2016-10-04
CPC Classification: G01D,G01K,G01L

Claim Text:
1. An optical sensing apparatus for measuring changes in pressure or force, the optical sensing apparatus comprising: first and second optical fibre portions with Bragg gratings; a sensing region for exposing both the first and second optical fibre portions with the Bragg gratings to changes in the pressure or force and in temperature; and a holder for holding the first and second optical fibre portions within the sensing region, the holder being provided in the form of a rigid member that is rigidly attached to the optical fibre portions at either side of the sensing region and the Bragg gratings; wherein, within the sensing region, the first and second optical fibre portions are arranged relative to each other such that the change in the force or pressure results in an increase in the optical property of one of the first and second optical fibre portions and a decrease in the optical property in the other one of the first and second optical fibre portions; wherein the apparatus is also arranged for measuring a change in temperature in a manner such that the change in temperature causes either an increase of the optical property of both optical fibre portions or a decrease of the optical property of both optical fibre portions; wherein the first and second optical fibre portions are oriented along a line; and wherein at least one of the first and second optical fibre portions is wound around the line at the sensing region.