| 摘要 |
<p>PURPOSE:To detect the presence or absence of a flame accurately even in the environment wherein a considerable quanitity of infrared rays are present in the vicinity, with almost no smoke generating, by detecting yielding gas by using optical fibers. CONSTITUTION:Light is emitted from a light source 7 through a light emitting optical fiber 2 and made to pass an interference gas cell 4 and a part to be measured 1. Part of the light reaches a light receiving optical fiber 3 through a filter cell 5. The other part of the light reaches a ligh receiving optical fiber 3' without passing the filter 5. Both light beams guided by the light receiving optical fibers 3 and 3' are received by a detector 6 and compared. In the filter cell 5, a gas including the component of the gas yielded by a flame in high concentration is put. In a compensating cell 8, a gas such as nitrogen and oxygen, which does not have absorption in the infrared ray part is put. When the flame is generated in the part to be measured 1, the arriving energy the light receiving optical fiber 3 is hardly changed. The arriving energy through the light receiving optical fiber 3' is largely changed.</p> |
