| 摘要 |
Remote sensing in an environment having temperatures greater than 300{C, using an optical fiber having a core (10), a cladding (20), and a metallic protective coating (30) on the cladding to protect a surface of the cladding, the cladding having a diameter greater than 150žm, and a thickness of at least 50žm. The larger diameter cladding means stress from the metallic protective layer can be reduced, giving lower optical loss and better hydrogen protection. A metal conduit (330) encapsulates the sensing fiber, and a pump evacuates the conduit to reduce hydrogen seepage. Ceramic splice protectors are used. OTDR is used to determine differential loss at different locations along the fiber. A reflect ive element at the far-end of the fiber eases calibration. |
