| 摘要 |
<p>PURPOSE:To measure optically the amount and concentration of hydrogen gas by using an optical fiber by providing a light source, a sensor part composed of the optical fiber, and a measuring means which measures the transmission loss of light. CONSTITUTION:Light from the light source 1 is separated by a half-mirror 3 into measurement light and reference light; and the measurement light is converted photoelectrically by a photodetector 7 after propagating in the optical fiber 5 constituting the sensor part and the reference light, on the other hand, is converted photoelectrically by a photodetector 9 for monitoring the output of the light source. Outputs of those photodetectors 7 and 9 are compared with each other by a computer 11 to calculate the transmission loss of the optical fiber 5. When this optical fiber 5 is placed in an H2 atmosphere, the transmission loss increases reversibly or inreversibly according to the kind of the core glass of the optical fiber 5 and the increment is calculated to measure the thickness of H2. The sensitivity of the photodetectors is increased preferably by winding the fiber 5 around a bobbin 13 for an increase in operation length or incorporating a heater 15 for the acceleration of reaction.</p> |
