| 摘要 |
PURPOSE:To enable to discriminate the airtight state of an arrester to be tested, by contrasting the commercial frequency discharge start voltage of the sample arrester in the air with said voltage under a vacuum. CONSTITUTION:Arrester 3 to be tested is placed in vacuum chamber 2, which is sealed. In this case, arrester 3 to be tested is connected electrically to voltage application device 1 outside vacuum chamber 2 and at the atmospheric pressure, the voltage application device is put into operation to raise the voltage, thereby measuring a commercial frequency discharge start voltage. Next, while vacuum chamber 2 remains sealed, vacuum pump 4 is operated to produce a prescribed vacuum in vacuum chamber 2 and a prescribed time later, the voltage application device is operated again to measure the commercial frequency discharge start voltage of arrester 3 to be tested. Then, a judgement is formed on the propriety of the airtight stage according to the existence of the difference between measured values at the atmospheric pressure and under a vacuum. |
