| 摘要 |
<p>PURPOSE:To enable self-trouble diagnosis at all times by closely disposing an optical fiber cable for projecting monitor light to an optical fiber cable for receiving light and detecting monitor light all the time. CONSTITUTION:An optical fiber cable 40 arranged outside a vessel from a light guide body 4 is composed of an optical fiber cable 40a for receiving light and an optical fiber cable 40b for projection, monitor light is applied from the optical fiber cable 40b for projection, and the monitor light is detected by the optical fiber cable 40a for receiving light. Monitor light and accident flashover light are discriminated by a waveform decision circuit 41 connected to the optioal fiber cable 40a for receiving light. Accordingly, a device capable of conducting self-trouble diagnosis at all times and having excellent reliability is acquired.</p> |
