在電(dian)(dian)力(li)系統中大(da)(da)型(xing)(xing)地網接(jie)地電(dian)(dian)阻的(de)(de)測試(shi)主要采(cai)用工(gong)頻大(da)(da)電(dian)(dian)流三(san)極法(fa)測量。為了(le)防(fang)止電(dian)(dian)網運(yun)行時產生的(de)(de)工(gong)頻干擾，提高測量結果的(de)(de)準確性，絕緣預(yu)防(fang)性試(shi)驗(yan)規(gui)程(cheng)規(gui)定：工(gong)頻大(da)(da)電(dian)(dian)流法(fa)的(de)(de)試(shi)驗(yan)電(dian)(dian)流不(bu)得小于(yu)30安培(pei)。由此(ci)，就出(chu)現(xian)了(le)試(shi)驗(yan)設備笨重，試(shi)驗(yan)過程(cheng)復雜(za)，試(shi)驗(yan)人員工(gong)作強度大(da)(da)，試(shi)驗(yan)時間長等諸多(duo)問(wen)題。 　　DWR型(xing)(xing)大(da)(da)型(xing)(xing)地網接(jie)地電(dian)(dian)阻測試(shi)儀，可測變(bian)電(dian)(dian)站(zhan)地網（4Ω）、水火(huo)電(dian)(dian)廠(chang)、微波站(zhan)（10Ω）、避雷針（10Ω）多(duo)用機型(xing)(xing)，采(cai)用了(le)新(xin)型(xing)(xing)異頻交