| 摘要 |
PURPOSE:To facilitate the connection, by providing a plurality of optical fibers successively in the direction of transmitting light while the diameter of the optical fibers is differentiated. CONSTITUTION:Optical fibers used for a flame monitor are provided in the plurality of optical fibers 10-12 in the direction of transmitting light and differentiated in the diameter. In other words, a light admitting optical fiber 10 mounted on a light admitting head has the largest outer diameter, for example, about 800mum in the outer diameter of a clad 10b formed in the perimeter of a core 10a. Then, a relay optical fiber 11 housed in an outer cylinder composing a monitor body shall be, for example, about 500mum in the outer diameter of a clad 11b. Then, an optical fiber 12 of the smallest diameter is connected to the relay optical fiber 11 and is made even smaller than the relay optical fiber 11. With such an arrangement, only damaged ones can be exchanged even when a damage takes place in a part of the optical fibers used, making the apparatus economical while facilitating the connection of the optical fibers. |
