| 摘要 |
<p>PROBLEM TO BE SOLVED: To exactly detect internal arc generation even in self-checking, by detecting the number of pulse in comparator output in unit time at a pulse number detector. SOLUTION: A check pulse generation part 10 for self-checking outputs predetermined number of pulse signals to an E/O converter 11. The E/O converter 11 emits checking light converted to light signal, which is radiated inside a tank via optical fiber 12. The irradiation checking light goes in a sensor 3, be sent to an O/E converter 5 via an optical fiber 4 and converted to electric signal which is amplified in an amplifier 6 and output to a comparator 7. The comparator 7 compares the amplified signal with noise level and generates the light emission inside the tank 1. The output of the comparator 7 is inputted in a pulse number detector 8. The pulse number detector 8 outputs alarm of self checking in the case the number of pulse in a unit time is the same, and outputs the alarm of inside arc generation in the case the number of pulse is different.</p> |
