System and method for uniform and localized wall thickness measurement using fiber optic sensors

System for determining variations in the wall thickness of a pressurized pipe, comprising:

• an optical fiber including a plurality of Fiber Bragg Gratings (FBGs);
• a mounting for securing the FBGs of the optical fiber over discrete portions of an exterior surface of a wall of a pressurized pipe such that strain in the discrete portions is transmitted to the FBGs, wherein a first FBG is located over a portion of said pipe expected to have negligible material loss and a second FBG is located over a portion of said pipe expected to have significant material loss;
• a light source and a light sensor coupled to the optical fiber, wherein the light sensor converts light reflected back from said FBGs into electrical signals, and
• a digital processor that converts said electrical signals into strain measurements, and that determines a wall thickness at least in part by comparing the strain measurements taken by said first and second FBGs.

A process for determining variations in the wall thickness of a pressurized pipe, comprising:

• mounting a first Fiber Bragg Grating (FBG) of an optical fiber over a discrete portion of an exterior surface of a wall of a pressurized pipe expected to have a full wall thickness;
• mounting a second FBG of the optical fiber over a discrete portion of the exterior surface of the wall of said pressurized pipe expected to have a thinner wall thickness of the pressurized pipe such that changes in the size of the discrete portions of the pipe apply strain to the FBGs;
• conducting light through an end of the optical fiber;
• converting light reflected from the first and second FBGs of the optical fiber into electrical signals indicative of a strain measurement,
• converting said strain measurement into a wall thickness;
• and
• determining a thickness of the thinner wall thickness by comparing strain measurements provided by the first and second FBGs.