| 摘要 |
PURPOSE:To specify a steel tower struck by lightning by providing a bypass to delay and guide an optical pulse to the width or above of the optical pulse at an optical fiber and providing an optical sensor to change the intensity of the leading pulse based on the information of respective measuring parts at the bypass. CONSTITUTION:A bypass 5 to delay and guide an optical pulse to the width or above of the optical pulse is provided and the bypass 5 is provided with an optical sensor 6 like a lightning detecting sensor to detect the presence and absence of the lightning at respective measuring parts with ON-OFF. When either of respective measuring parts, namely, respective steel towers 1 is struck by lighting, the lightning detecting sensor to measure with the measuring part interrupts the light path to pass through the bypass to provide the lightning detecting sensor and reduces the intensity. For this reason, a light receiver 4 receives a receiving pulse 9 in which a detecting pulse 8 corresponding to the bypass 5 is dissipated or the intensity is lower than the intensity of other detecting pulse 8, and thus, the steel tower 1 struck by the lightning can be specified. |
