測試接地電阻的常用方法有(you)哪些？

接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)阻(zu)(zu)是(shi)用于(yu)測量接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)狀態是(shi)否良好的(de)(de)重(zhong)要參數。電(dian)(dian)(dian)流(liu)(liu)從(cong)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)裝置流(liu)(liu)入大(da)地(di)(di)(di)(di)(di)(di)(di)然后流(liu)(liu)經大(da)地(di)(di)(di)(di)(di)(di)(di)到另一個(ge)(ge)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)體(ti)(ti)或(huo)擴(kuo)散到遠處的(de)(de)電(dian)(dian)(dian)阻(zu)(zu)。它包括接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)線(xian)和(he)(he)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)體(ti)(ti)本身。電(dian)(dian)(dian)阻(zu)(zu)器，接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)體(ti)(ti)和(he)(he)大(da)地(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)阻(zu)(zu)之(zhi)間的(de)(de)接(jie)(jie)觸電(dian)(dian)(dian)阻(zu)(zu)，以及兩個(ge)(ge)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)體(ti)(ti)之(zhi)間的(de)(de)大(da)地(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)阻(zu)(zu)或(huo)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)體(ti)(ti)的(de)(de)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)阻(zu)(zu)達(da)到無窮大(da)，接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)阻(zu)(zu)的(de)(de)大(da)小直接(jie)(jie)反映了(le)電(dian)(dian)(dian)氣設(she)備與(yu)“地(di)(di)(di)(di)(di)(di)(di)面”之(zhi)間的(de)(de)接(jie)(jie)觸程度，也反映了(le)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)網的(de)(de)規模。接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)電(dian)(dian)(dian)阻(zu)(zu)的(de)(de)概(gai)念(nian)僅適用于(yu)小型接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)網。隨著(zhu)接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)網的(de)(de)覆蓋面積的(de)(de)增加和(he)(he)土(tu)壤電(dian)(dian)(dian)阻(zu)(zu)率的(de)(de)降低，接(jie)(jie)地(di)(di)(di)(di)(di)(di)(di)阻(zu)(zu)抗的(de)(de)電(dian)(dian)(dian)感成分(fen)變得越來(lai)越重(zhong)要。

測試接地電阻的常用方法有以下幾(ji)點：

1、兩(liang)點法

通(tong)過(guo)這種方法(fa)，通(tong)過(guo)將P1和C1端(duan)子連接(jie)到要測試的接(jie)地電(dian)(dian)極(ji)來測量一(yi)系列兩個電(dian)(dian)極(ji)的電(dian)(dian)阻，P2和C2連接(jie)到單獨的全金屬(shu)接(jie)地點。

兩點法(fa)是獲得(de)接地電阻(zu)讀數的蕞簡(jian)單(dan)方法(fa)，但它不如三點法(fa)準確，只能用作后(hou)的手段。這(zhe)對(dui)于快速測試連(lian)接點之(zhi)間的連(lian)接和(he)導(dao)體有效方式。

注意：測得的接地電極必須與(yu)輔(fu)助(zhu)觸點(dian)相(xiang)距足夠遠，以超(chao)過(guo)其沖擊范圍。

2、三點法

三點(dian)(dian)法(fa)是*可靠的(de)測試方法(fa)。它(ta)用于測量接(jie)地(di)電(dian)極(ji)的(de)接(jie)地(di)電(dian)阻，使用四(si)端(duan)子測試儀，將儀器上的(de)P1和C1端(duan)子跨接(jie)并(bing)連接(jie)到被測接(jie)地(di)電(dian)極(ji)，同時(shi)將C2參考桿直(zhi)接(jie)打入(ru)(ru)地(di)面，并(bing)盡可能遠(yuan)離(li)被測電(dian)極(ji)，然后，潛在的(de)參考點(dian)(dian)P2大(da)約(yue)在C1和C2之間的(de)一條直(zhi)線上被驅(qu)動了一定數量的(de)點(dian)(dian)進入(ru)(ru)地(di)球，記錄(lu)每個P2點(dian)(dian)的(de)電(dian)阻讀數。

3、四點法

此方(fang)法(fa)是常用的(de)(de)測量土壤電阻率的(de)(de)方(fang)法(fa)，這(zhe)對設計電氣接地系統很重(zhong)要，用這(zhe)種方(fang)法(fa)，將四個(ge)小尺寸的(de)(de)電極以相(xiang)同的(de)(de)深度(du)和相(xiang)等的(de)(de)距離(li)（直線）打入地下(xia)并進行(xing)測量。

土壤的(de)水(shui)分和鹽分含(han)量(liang)從根本上(shang)影(ying)響(xiang)其電(dian)(dian)阻(zu)率，土壤電(dian)(dian)阻(zu)率的(de)測量(liang)也受到現(xian)有(you)接地電(dian)(dian)極(ji)的(de)影(ying)響(xiang)；如果與土壤接觸的(de)埋入式導電(dian)(dian)物體足(zu)夠(gou)靠近以(yi)改(gai)變(bian)測試電(dian)(dian)流模(mo)式，則讀數(shu)將無效，對于大型或(huo)長物體尤(you)其如此。

4、鉗(qian)位法

鉗位法(fa)的*之處在于它(ta)無(wu)需斷開接地(di)(di)(di)系統即可測量(liang)電阻。它(ta)既快速又簡單，并且在測量(liang)中還包括接地(di)(di)(di)和整體接地(di)(di)(di)電阻。

通過(guo)將鉗(qian)型接(jie)地(di)電(dian)(dian)阻測(ce)(ce)量儀(yi)“夾緊”在被測(ce)(ce)接(jie)地(di)電(dian)(dian)極周圍，這類似于(yu)使用(yong)萬用(yong)表電(dian)(dian)流鉗(qian)測(ce)(ce)量電(dian)(dian)流的(de)方法(fa)，測(ce)(ce)試儀(yi)通過(guo)發射線圈施加已知電(dian)(dian)壓，而無需(xu)直接(jie)電(dian)(dian)連接(jie)，并測(ce)(ce)量通過(guo)電(dian)(dian)流的(de)電(dian)(dian)流，接(jie)收線圈，該測(ce)(ce)試在高頻下進行(xing)，以使變壓器盡可能小且實用(yong)。