a．10KV10000V絕緣電阻測試儀環境(jing)溫濕度
一般材料(liao)的電(dian)阻(zu)值隨環境(jing)溫濕度的升高而(er)減小。相對而(er)言，表面電(dian)阻(zu)(率(lv)(lv))對環境(jing)濕度比較(jiao)敏(min)感，而(er)體電(dian)阻(zu)(率(lv)(lv))則對溫度較(jiao)為敏(min)感。10KV10000V絕緣電阻測試儀濕度增加(jia)，表(biao)面(mian)泄漏增大，體電導(dao)電流(liu)也會增加(jia)。溫度升高(gao)，載流(liu)子的(de)(de)(de)(de)運動速(su)率(lv)加(jia)快(kuai)，介(jie)質(zhi)材料的(de)(de)(de)(de)吸收電流(liu)和電導(dao)電流(liu)會相應增加(jia)，據有關資料報道(dao)，一般介(jie)質(zhi)在7 0 C時的(de)(de)(de)(de)電阻值僅有20 C時的(de)(de)(de)(de)10 ％。因此(ci)，測量材料的(de)(de)(de)(de)電阻時，必(bi)須指明試樣與環(huan)境(jing)達(da)到平衡的(de)(de)(de)(de)溫濕度。
b．10KV絕緣電(dian)阻測試儀測試電(dian)壓(電(dian)場強度)
介質材(cai)料(liao)的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)(率)值(zhi)(zhi)一般不(bu)能在很寬的(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)范圍內保(bao)持不(bu)變，即歐(ou)姆定律(lv)對此(ci)(ci)并不(bu)適用。常(chang)溫(wen)條件下(xia)，在較(jiao)低(di)的(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)范圍內，電(dian)(dian)(dian)(dian)(dian)導電(dian)(dian)(dian)(dian)(dian)流(liu)隨外加(jia)(jia)電(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)增(zeng)加(jia)(jia)而線性增(zeng)加(jia)(jia)，材(cai)料(liao)的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)值(zhi)(zhi)保(bao)持不(bu)變。超過一定電(dian)(dian)(dian)(dian)(dian)壓(ya)后，由于離子化運動加(jia)(jia)劇，電(dian)(dian)(dian)(dian)(dian)導電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)增(zeng)加(jia)(jia)遠比測試電(dian)(dian)(dian)(dian)(dian)壓(ya)增(zeng)加(jia)(jia)的(de)快，材(cai)料(liao)呈現的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)值(zhi)(zhi)迅速降(jiang)低(di)。由此(ci)(ci)可(ke)見，外加(jia)(jia)測試電(dian)(dian)(dian)(dian)(dian)壓(ya)越(yue)高，材(cai)料(liao)的(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)值(zhi)(zhi)越(yue)低(di)，以(yi)致在不(bu)同電(dian)(dian)(dian)(dian)(dian)壓(ya)下(xia)測試得到的(de)材(cai)料(liao)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)值(zhi)(zhi)可(ke)能有較(jiao)大的(de)差別。
值(zhi)得注意的是(shi)，導致材料電(dian)(dian)(dian)阻(zu)值(zhi)變(bian)化(hua)的決定因(yin)素是(shi)測試時的電(dian)(dian)(dian)場(chang)強(qiang)度，而不是(shi)測試電(dian)(dian)(dian)壓。對(dui)相同(tong)(tong)的測試電(dian)(dian)(dian)壓，若測試電(dian)(dian)(dian)極之間的距(ju)離不同(tong)(tong)，對(dui)材料電(dian)(dian)(dian)阻(zu)率的測試結果也(ye)將不同(tong)(tong)，正負電(dian)(dian)(dian)極之間的距(ju)離越小，測試值(zhi)也(ye)越小。
c．10KV10000V絕緣電阻測試儀測試時間
用(yong)一定(ding)的直流(liu)電(dian)(dian)(dian)(dian)壓(ya)對被測(ce)材料加壓(ya)時(shi)，被測(ce)材料上的電(dian)(dian)(dian)(dian)流(liu)不是瞬時(shi)達(da)到(dao)穩(wen)定(ding)值的，而是有一衰減過程。在(zai)加壓(ya)的同(tong)時(shi)，流(liu)過較大的充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)，接(jie)著是比(bi)較長時(shi)間(jian)緩慢減小的吸收電(dian)(dian)(dian)(dian)流(liu)，最后達(da)到(dao)比(bi)較平穩(wen)的電(dian)(dian)(dian)(dian)導電(dian)(dian)(dian)(dian)流(liu)。被測(ce)電(dian)(dian)(dian)(dian)阻值越高，達(da)到(dao)平衡的時(shi)間(jian)則(ze)越長。因此，測(ce)量時(shi)為了正確(que)讀取被測(ce)電(dian)(dian)(dian)(dian)阻值，應在(zai)穩(wen)定(ding)后讀取數(shu)值或取加壓(ya)1分鐘后的讀數(shu)值。
另外，高絕緣(yuan)材(cai)料(liao)的電(dian)阻(zu)值還與其帶電(dian)的歷史有關(guan)。為準確評價(jia)材(cai)料(liao)的靜電(dian)性能，在對(dui)材(cai)料(liao)進(jin)行電(dian)阻(zu)(率)測(ce)(ce)試時，應首先對(dui)其進(jin)行消(xiao)電(dian)處理，并靜置一(yi)定的時間，靜置時間可(ke)取5分鐘，然后(hou)，再按測(ce)(ce)量程序測(ce)(ce)試。一(yi)般而言，對(dui)一(yi)種材(cai)料(liao)的測(ce)(ce)試，至少應隨機抽取3 ～ 5個試樣進(jin)行測(ce)(ce)試，以其平(ping)均(jun)值作為測(ce)(ce)試結果
