a．10KV10000V絕緣電阻測試儀環境溫(wen)濕度(du)
一般材料的電(dian)阻值隨環境溫濕度(du)的升高而減小。相對而言，表面電(dian)阻(率)對環境濕度(du)比較敏感，而體(ti)電(dian)阻(率)則對溫度(du)較為敏感。10KV10000V絕緣電阻測試儀濕度增(zeng)加(jia)(jia)，表面泄(xie)漏(lou)增(zeng)大，體電(dian)導(dao)電(dian)流(liu)也會增(zeng)加(jia)(jia)。溫度升(sheng)高，載流(liu)子的(de)(de)運動(dong)速率加(jia)(jia)快(kuai)，介質材(cai)料的(de)(de)吸收電(dian)流(liu)和(he)電(dian)導(dao)電(dian)流(liu)會相應增(zeng)加(jia)(jia)，據有關資料報道，一般介質在7 0 C時的(de)(de)電(dian)阻值僅有20 C時的(de)(de)10 ％。因此，測量材(cai)料的(de)(de)電(dian)阻時，必須(xu)指明試(shi)樣與環境達到平衡的(de)(de)溫濕度。
b．10KV絕緣電阻測試(shi)儀測試(shi)電壓(電場強度)
介質材(cai)(cai)料(liao)的(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)(率)值一(yi)般不(bu)能在(zai)(zai)很寬(kuan)的(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)范(fan)圍內保(bao)持(chi)不(bu)變，即歐姆定律對此并不(bu)適用。常溫條件下(xia)(xia)，在(zai)(zai)較低(di)的(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)范(fan)圍內，電(dian)(dian)(dian)(dian)(dian)導電(dian)(dian)(dian)(dian)(dian)流隨外(wai)加(jia)(jia)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)增加(jia)(jia)而線(xian)性增加(jia)(jia)，材(cai)(cai)料(liao)的(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)值保(bao)持(chi)不(bu)變。超(chao)過一(yi)定電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)后(hou)，由于離子化運動加(jia)(jia)劇(ju)，電(dian)(dian)(dian)(dian)(dian)導電(dian)(dian)(dian)(dian)(dian)流的(de)(de)增加(jia)(jia)遠比測(ce)(ce)試電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)增加(jia)(jia)的(de)(de)快，材(cai)(cai)料(liao)呈現(xian)的(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)值迅(xun)速降低(di)。由此可見，外(wai)加(jia)(jia)測(ce)(ce)試電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)越高，材(cai)(cai)料(liao)的(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)值越低(di)，以致在(zai)(zai)不(bu)同電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)下(xia)(xia)測(ce)(ce)試得到(dao)的(de)(de)材(cai)(cai)料(liao)電(dian)(dian)(dian)(dian)(dian)阻(zu)值可能有較大的(de)(de)差別。
值(zhi)得注意的(de)是，導致材料電(dian)(dian)阻(zu)值(zhi)變化的(de)決定(ding)因素是測(ce)試(shi)(shi)時的(de)電(dian)(dian)場強(qiang)度，而不(bu)是測(ce)試(shi)(shi)電(dian)(dian)壓。對(dui)相(xiang)同的(de)測(ce)試(shi)(shi)電(dian)(dian)壓，若(ruo)測(ce)試(shi)(shi)電(dian)(dian)極之間的(de)距(ju)離(li)不(bu)同，對(dui)材料電(dian)(dian)阻(zu)率的(de)測(ce)試(shi)(shi)結果也將不(bu)同，正負電(dian)(dian)極之間的(de)距(ju)離(li)越小(xiao)，測(ce)試(shi)(shi)值(zhi)也越小(xiao)。
c．10KV10000V絕緣電阻測試儀測試時間
用一定(ding)(ding)的(de)(de)(de)(de)(de)直流電(dian)壓對被測材料加壓時(shi)，被測材料上的(de)(de)(de)(de)(de)電(dian)流不是瞬時(shi)達到穩定(ding)(ding)值(zhi)(zhi)的(de)(de)(de)(de)(de)，而是有一衰減(jian)過(guo)程。在加壓的(de)(de)(de)(de)(de)同時(shi)，流過(guo)較(jiao)(jiao)大的(de)(de)(de)(de)(de)充(chong)電(dian)電(dian)流，接著是比(bi)較(jiao)(jiao)長(chang)時(shi)間緩慢減(jian)小的(de)(de)(de)(de)(de)吸(xi)收電(dian)流，最后達到比(bi)較(jiao)(jiao)平(ping)穩的(de)(de)(de)(de)(de)電(dian)導電(dian)流。被測電(dian)阻值(zhi)(zhi)越高，達到平(ping)衡(heng)的(de)(de)(de)(de)(de)時(shi)間則(ze)越長(chang)。因此，測量(liang)時(shi)為了(le)正確讀取被測電(dian)阻值(zhi)(zhi)，應(ying)在穩定(ding)(ding)后讀取數(shu)值(zhi)(zhi)或取加壓1分鐘后的(de)(de)(de)(de)(de)讀數(shu)值(zhi)(zhi)。
另外(wai)，高絕緣材料(liao)的電(dian)阻值還與(yu)其帶電(dian)的歷史有關。為準確評價(jia)材料(liao)的靜電(dian)性能，在對(dui)材料(liao)進(jin)(jin)行電(dian)阻(率(lv))測(ce)試時，應(ying)首先(xian)對(dui)其進(jin)(jin)行消(xiao)電(dian)處理(li)，并靜置一(yi)定(ding)的時間(jian)，靜置時間(jian)可取5分鐘，然后，再(zai)按測(ce)量(liang)程序測(ce)試。一(yi)般而言，對(dui)一(yi)種材料(liao)的測(ce)試，至少應(ying)隨(sui)機抽取3 ～ 5個(ge)試樣進(jin)(jin)行測(ce)試，以其平均值作為測(ce)試結果