電纜故障(zhang)測(ce)試儀(yi)根據故障(zhang)的(de)(de)探(tan)測(ce)原理，當(dang)(dang)儀(yi)器(qi)(qi)處于(yu)閃絡觸(chu)發(fa)方式時(shi)(shi)，故障(zhang)點瞬(shun)(shun)時(shi)(shi)擊穿(chuan)放電所(suo)形(xing)成的(de)(de)閃絡回波是(shi)隨(sui)機(ji)的(de)(de)單次(ci)瞬(shun)(shun)態(tai)波形(xing)，因此測(ce)試儀(yi)器(qi)(qi)應具(ju)備存(cun)儲(chu)示波器(qi)(qi)的(de)(de)功能，可(ke)捕獲(huo)和(he)顯示單次(ci)瞬(shun)(shun)態(tai)波形(xing)。本(ben)儀(yi)器(qi)(qi)采用數字存(cun)儲(chu)技術，利用高速(su)A/D轉(zhuan)換器(qi)(qi)采樣，將輸入的(de)(de)瞬(shun)(shun)態(tai)模擬(ni)信號(hao)實時(shi)(shi)地轉(zhuan)換成數字信號(hao)，存(cun)儲(chu)在高速(su)存(cun)儲(chu)器(qi)(qi)中，經(jing)CPU微處理器(qi)(qi)處理后，送至LCD顯示控制(zhi)電路，變為(wei)時(shi)(shi)序點陣(zhen)信息(xi)，于(yu)是(shi)在LCD屏(ping)幕上顯示當(dang)(dang)前采樣的(de)(de)波形(xing)參數。
使用(yong)過程中常見的故障及注意事項
1.脈沖法測試(shi)時，注意要甩掉局內所有(you)設備，在(zai)外線上進行測量(liang)。
2.使用閃(shan)絡法測試時，必須將觸發工作(zuo)方(fang)式開關置于“閃(shan)絡”位置。
3.在使用(yong)直閃(shan)法或沖閃(shan)法測試時，要注意(yi)人身安全(quan)及(ji)設備安全(quan)。必須接好地(di)線(xian)。
4.在(zai)閃絡(luo)法測試結(jie)束(shu)后，切斷電(dian)(dian)(dian)(dian)源，拆除本儀器(qi)(qi)與(yu)高壓測試裝置(zhi)的(de)連接線，再(zai)(zai)對高壓電(dian)(dian)(dian)(dian)容器(qi)(qi)和電(dian)(dian)(dian)(dian)纜的(de)所貯電(dian)(dian)(dian)(dian)荷進行放電(dian)(dian)(dian)(dian)。放電(dian)(dian)(dian)(dian)時，應先加限(xian)流(liu)電(dian)(dian)(dian)(dian)阻R限(xian)制放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)以使電(dian)(dian)(dian)(dian)流(liu)緩(huan)慢放電(dian)(dian)(dian)(dian)，待電(dian)(dian)(dian)(dian)容器(qi)(qi)上電(dian)(dian)(dian)(dian)壓降低后，再(zai)(zai)直接對地(di)放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)路中電(dian)(dian)(dian)(dian)阻為零，瞬(shun)間放電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)可高達幾百安(an)培，將發生嚴(yan)重的(de)設(she)備或人身事故。
5.在直閃(shan)法測試(shi)過程中，必須注(zhu)意監(jian)視故障的泄漏電流若電流突然增大，故障閃(shan)絡現(xian)象未曾出(chu)現(xian)，應立即降低試(shi)驗(yan)電壓，改用沖閃(shan)法測試(shi)。
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