| 摘要 |
<p>PURPOSE:To protect an optical fiber mechanically and bring a material to be detected into contact to the optical fiber by providing pipe wall of a metal pipe containing the optical fiber with a plurality of openings at a certain interval in the length direction. CONSTITUTION:An optical fiber 1 provided with a resin coating layer on an optical fiber glass is contained in a metal (such as stainless steel) pipe 2. On the pipe wall of the metal pipe 2, a plurality of openings 3 with a round or square shape are provided at a certain interval in the length direction. Therefore, such measured object fluids as gas, oil, water, etc., invade in the metal pipe 2 through the openings 3. By this the measured objects come in contact with the optical fiber 1 and thus measurement is possible. By providing the openings 3 with selective transmission film as necessary, only a material to be measured is allowed to invade in the metal pipe 2 and other materials than to be measured which give bad effect to the optical fiber 1 can be eliminated.</p> |
