交(jiao)(jiao)流(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表可采(cai)用電(dian)(dian)(dian)(dian)(dian)磁(ci)系(xi)或(huo)電(dian)(dian)(dian)(dian)(dian)動(dong)系(xi)測(ce)量(liang)(liang)機構(gou)。為使磁(ci)電(dian)(dian)(dian)(dian)(dian)系(xi)測(ce)量(liang)(liang)機構(gou)也(ye)能用于(yu)測(ce)量(liang)(liang)交(jiao)(jiao)流(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，可利(li)用整(zheng)流(liu)(liu)(liu)(liu)器(qi)或(huo)熱電(dian)(dian)(dian)(dian)(dian)偶(ou)等器(qi)件先(xian)將交(jiao)(jiao)流(liu)(liu)(liu)(liu)轉換為直流(liu)(liu)(liu)(liu);由它們(men)組合而成(cheng)的(de)電(dian)(dian)(dian)(dian)(dian)表分(fen)別稱為整(zheng)流(liu)(liu)(liu)(liu)式(shi)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表(見整(zheng)流(liu)(liu)(liu)(liu)式(shi)電(dian)(dian)(dian)(dian)(dian)表)、熱電(dian)(dian)(dian)(dian)(dian)式(shi)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表。為擴大量(liang)(liang)程以(yi)測(ce)量(liang)(liang)大電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，正泰電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表供應商，整(zheng)流(liu)(liu)(liu)(liu)式(shi)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表也(ye)采(cai)用分(fen)流(liu)(liu)(liu)(liu)器(qi);電(dian)(dian)(dian)(dian)(dian)動(dong)系(xi)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表的(de)做法同前;電(dian)(dian)(dian)(dian)(dian)磁(ci)系(xi)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表則是加粗線圈(quan)導線、減少匝數。對于(yu)更大的(de)測(ce)量(liang)(liang)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)值需配合電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)互感器(qi)使用。通常可利(li)用分(fen)流(liu)(liu)(liu)(liu)器(qi)和交(jiao)(jiao)流(liu)(liu)(liu)(liu)數字電(dian)(dian)(dian)(dian)(dian)壓表構(gou)成(cheng)交(jiao)(jiao)流(liu)(liu)(liu)(liu)數字電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)表。

電流表內(nei)外接法產生誤(wu)差的原因

當(dang)選(xuan)用外(wai)接(jie)法時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓表與電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)并聯，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓表的(de)(de)(de)讀數(shu)就是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)兩(liang)端(duan)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，但電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)表測(ce)(ce)量的(de)(de)(de)是(shi)通過電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓表的(de)(de)(de)總電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，連云港正泰(tai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)表，因此測(ce)(ce)量值(zhi)要小于真(zhen)實(shi)值(zhi)，實(shi)際(ji)上測(ce)(ce)量的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)值(zhi)是(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓表內電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)并聯的(de)(de)(de)阻(zu)(zu)(zu)值(zhi)。如果電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)Rx的(de)(de)(de)值(zhi)遠小于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓表的(de)(de)(de)內阻(zu)(zu)(zu)RV，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓表分去(qu)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)很小，這時電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)表測(ce)(ce)量的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)就接(jie)近于通過電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，所以外(wai)接(jie)法適合于測(ce)(ce)小電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)。

電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)是根據通電(dian)(dian)(dian)(dian)(dian)(dian)導體在(zai)磁(ci)(ci)(ci)場(chang)中受(shou)磁(ci)(ci)(ci)場(chang)力的(de)(de)作用而制(zhi)成的(de)(de)。電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)內(nei)部有一(yi)(yi)(yi)永磁(ci)(ci)(ci)體，在(zai)極(ji)間產生磁(ci)(ci)(ci)場(chang)，在(zai)磁(ci)(ci)(ci)場(chang)中有一(yi)(yi)(yi)個線圈(quan)(quan)，線圈(quan)(quan)兩端各有一(yi)(yi)(yi)個游絲彈簧，彈簧各連(lian)接(jie)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)的(de)(de)一(yi)(yi)(yi)個接(jie)線柱，正泰電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)哪家好，在(zai)彈簧與線圈(quan)(quan)間由(you)一(yi)(yi)(yi)個轉(zhuan)軸連(lian)接(jie)，在(zai)轉(zhuan)軸相對于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)的(de)(de)前端，有一(yi)(yi)(yi)個指(zhi)針。指(zhi)針偏(pian)轉(zhuan)。由(you)于(yu)磁(ci)(ci)(ci)場(chang)力的(de)(de)大小隨電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)增大而增大，所以就可(ke)以通過指(zhi)針的(de)(de)偏(pian)轉(zhuan)程度來觀察電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)的(de)(de)大小。一(yi)(yi)(yi)般可(ke)直(zhi)接(jie)測(ce)量(liang)(liang)微安或毫安數(shu)量(liang)(liang)級的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)，為測(ce)更大的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)，電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)應(ying)有并聯電(dian)(dian)(dian)(dian)(dian)(dian)阻器（又稱分流(liu)(liu)(liu)(liu)(liu)器）。主要采(cai)用磁(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)系電(dian)(dian)(dian)(dian)(dian)(dian)表(biao)的(de)(de)測(ce)量(liang)(liang)機構。分流(liu)(liu)(liu)(liu)(liu)器的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)阻值要使(shi)滿(man)量(liang)(liang)程電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)通過時，電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)滿(man)偏(pian)轉(zhuan)，即電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)指(zhi)示達到醉大。