WEIGEL電流表EQ144K/1A/20A 翊霈優質供應

WEIGEL電流表EQ144K/1A/20A 翊霈優質供應

檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)是(shi)磁(ci)(ci)電(dian)(dian)式儀表(biao)，它(ta)是(shi)根據載流(liu)(liu)(liu)(liu)(liu)線(xian)(xian)圈(quan)(quan)在(zai)(zai)磁(ci)(ci)場(chang)(chang)(chang)中(zhong)(zhong)受到(dao)力矩而偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)的(de)(de)(de)(de)原理制成的(de)(de)(de)(de)。普通電(dian)(dian)表(biao)中(zhong)(zhong)線(xian)(xian)圈(quan)(quan)是(shi)安放在(zai)(zai)軸(zhou)承(cheng)上，用(yong)(yong)(yong)彈簧游(you)絲(si)來維持平(ping)衡(heng)(heng)(heng)，用(yong)(yong)(yong)指針來指示偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)。由(you)于(yu)(yu)軸(zhou)承(cheng)有(you)摩(mo)擦，被測(ce)(ce)電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)不能太弱。檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)使(shi)(shi)(shi)用(yong)(yong)(yong)極細(xi)的(de)(de)(de)(de)金(jin)屬懸(xuan)絲(si)代替軸(zhou)承(cheng)懸(xuan)掛(gua)在(zai)(zai)磁(ci)(ci)場(chang)(chang)(chang)中(zhong)(zhong)，由(you)于(yu)(yu)懸(xuan)絲(si)細(xi)而長(chang)，反抗力矩很(hen)小(xiao)(xiao)(xiao)，所以有(you)很(hen)弱的(de)(de)(de)(de)電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)通過(guo)(guo)線(xian)(xian)圈(quan)(quan)就(jiu)(jiu)足以使(shi)(shi)(shi)它(ta)產(chan)生顯著的(de)(de)(de)(de)偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)。因而檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)比一(yi)般的(de)(de)(de)(de)電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)表(biao)靈(ling)敏(min)的(de)(de)(de)(de)多，可以測(ce)(ce)量(liang)微(wei)電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)（10-7~10-10A）或者(zhe)微(wei)電(dian)(dian)壓（10-3~10-6V），如光(guang)電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)、生理電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)、溫差電(dian)(dian)動(dong)(dong)(dong)勢(shi)等。*記錄神經動(dong)(dong)(dong)作電(dian)(dian)位(wei)，就(jiu)(jiu)是(shi)用(yong)(yong)(yong)此(ci)類儀器實現的(de)(de)(de)(de)。以光(guang)點式檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)為(wei)例(li)，檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)由(you)三(san)部(bu)(bu)分(fen)組成：(1)磁(ci)(ci)場(chang)(chang)(chang)部(bu)(bu)分(fen)：由(you)永磁(ci)(ci)鐵(N,S)產(chan)生磁(ci)(ci)場(chang)(chang)(chang)，圓柱形軟鐵心(J)使(shi)(shi)(shi)氣(qi)隙中(zhong)(zhong)磁(ci)(ci)場(chang)(chang)(chang)呈(cheng)均勻輻射(she)(she)狀(zhuang)(zhuang)。(2)偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)部(bu)(bu)分(fen)：能在(zai)(zai)氣(qi)隙中(zhong)(zhong)轉(zhuan)(zhuan)動(dong)(dong)(dong)的(de)(de)(de)(de)矩形線(xian)(xian)圈(quan)(quan)C及(ji)從上下拉緊(jin)線(xian)(xian)圈(quan)(quan)的(de)(de)(de)(de)金(jin)屬張絲(si)E,只要(yao)有(you)很(hen)小(xiao)(xiao)(xiao)的(de)(de)(de)(de)力矩作用(yong)(yong)(yong)，就(jiu)(jiu)能使(shi)(shi)(shi)線(xian)(xian)圈(quan)(quan)偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)。(3)讀(du)數(shu)部(bu)(bu)分(fen)：小(xiao)(xiao)(xiao)鏡M固定(ding)在(zai)(zai)動(dong)(dong)(dong)圈(quan)(quan)上，它(ta)把光(guang)源射(she)(she)進(jin)來的(de)(de)(de)(de)光(guang)束反射(she)(she)到(dao)標(biao)尺上形成一(yi)個(ge)光(guang)標(biao)，當電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)流(liu)(liu)(liu)(liu)(liu)過(guo)(guo)動(dong)(dong)(dong)圈(quan)(quan)時(shi)(shi)，動(dong)(dong)(dong)圈(quan)(quan)受力偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)而帶動(dong)(dong)(dong)小(xiao)(xiao)(xiao)鏡M轉(zhuan)(zhuan)過(guo)(guo)?角，因而反射(she)(she)光(guang)束偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)的(de)(de)(de)(de)角度為(wei),光(guang)標(biao)在(zai)(zai)標(biao)尺上移動(dong)(dong)(dong)的(de)(de)(de)(de)距離(li)n=L*α，L為(wei)小(xiao)(xiao)(xiao)鏡到(dao)標(biao)尺的(de)(de)(de)(de)距離(li)，實際(ji)上阻(zu)(zu)(zu)(zu)尼(ni)總是(shi)存在(zai)(zai)的(de)(de)(de)(de),當R≠∞,D≠0時(shi)(shi)有(you)三(san)種運動(dong)(dong)(dong)狀(zhuang)(zhuang)態(tai)(tai)(tai).1)欠阻(zu)(zu)(zu)(zu)尼(ni)狀(zhuang)(zhuang)態(tai)(tai)(tai):此(ci)時(shi)(shi)外電(dian)(dian)阻(zu)(zu)(zu)(zu)R較大(da)，β<ω,動(dong)(dong)(dong)圈(quan)(quan)以平(ping)衡(heng)(heng)(heng)位(wei)置為(wei)中(zhong)(zhong)心作衰(shuai)減(jian)振(zhen)動(dong)(dong)(dong)，并且逐(zhu)漸(jian)趨緊(jin)于(yu)(yu)平(ping)衡(heng)(heng)(heng)位(wei)置。2)臨(lin)界(jie)阻(zu)(zu)(zu)(zu)尼(ni)狀(zhuang)(zhuang)態(tai)(tai)(tai):R=Rc,β=ω,動(dong)(dong)(dong)圈(quan)(quan)無振(zhen)動(dong)(dong)(dong)的(de)(de)(de)(de)很(hen)快達(da)(da)(da)到(dao)平(ping)衡(heng)(heng)(heng)位(wei)置，此(ci)時(shi)(shi)的(de)(de)(de)(de)外電(dian)(dian)阻(zu)(zu)(zu)(zu)稱為(wei)臨(lin)界(jie)電(dian)(dian)阻(zu)(zu)(zu)(zu)Rc，一(yi)般來說，檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)的(de)(de)(de)(de)臨(lin)界(jie)阻(zu)(zu)(zu)(zu)尼(ni)狀(zhuang)(zhuang)態(tai)(tai)(tai)是(shi)它(ta)的(de)(de)(de)(de)理想工作狀(zhuang)(zhuang)態(tai)(tai)(tai)。3)過(guo)(guo)阻(zu)(zu)(zu)(zu)尼(ni)狀(zhuang)(zhuang)態(tai)(tai)(tai):當β>ω,即(ji)R<Rc,此(ci)時(shi)(shi)動(dong)(dong)(dong)圈(quan)(quan)也是(shi)做單向偏(pian)(pian)(pian)(pian)轉(zhuan)(zhuan)運動(dong)(dong)(dong)，緩慢的(de)(de)(de)(de)趨向平(ping)衡(heng)(heng)(heng)位(wei)置。R越小(xiao)(xiao)(xiao)，到(dao)達(da)(da)(da)平(ping)衡(heng)(heng)(heng)位(wei)置的(de)(de)(de)(de)時(shi)(shi)間越長(chang)。因為(wei)過(guo)(guo)阻(zu)(zu)(zu)(zu)尼(ni)運動(dong)(dong)(dong)中(zhong)(zhong)，動(dong)(dong)(dong)圈(quan)(quan)到(dao)達(da)(da)(da)平(ping)衡(heng)(heng)(heng)的(de)(de)(de)(de)時(shi)(shi)間長(chang)，而且不易判斷動(dong)(dong)(dong)圈(quan)(quan)是(shi)否到(dao)達(da)(da)(da)平(ping)衡(heng)(heng)(heng)位(wei)置，因此(ci)它(ta)對于(yu)(yu)測(ce)(ce)量(liang)是(shi)不利的(de)(de)(de)(de)。由(you)于(yu)(yu)檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)很(hen)靈(ling)敏(min)，一(yi)般通過(guo)(guo)電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)不能超過(guo)(guo)1μA。電(dian)(dian)壓經過(guo)(guo)兩次(ci)分(fen)壓后得(de)到(dao)很(hen)小(xiao)(xiao)(xiao)的(de)(de)(de)(de)電(dian)(dian)壓(常小(xiao)(xiao)(xiao)于(yu)(yu)1mV)后才加到(dao)檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)電(dian)(dian)路中(zhong)(zhong)。第(di)一(yi)次(ci)采(cai)(cai)用(yong)(yong)(yong)滑線(xian)(xian)變阻(zu)(zu)(zu)(zu)器分(fen)壓，第(di)二次(ci)采(cai)(cai)用(yong)(yong)(yong)固定(ding)電(dian)(dian)阻(zu)(zu)(zu)(zu)R1/R0?≈10-3~10-4的(de)(de)(de)(de)數(shu)量(liang)級分(fen)壓。K2是(shi)換向開關(guan)，用(yong)(yong)(yong)它(ta)可以變換過(guo)(guo)檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)的(de)(de)(de)(de)電(dian)(dian)流(liu)(liu)(liu)(liu)(liu)方(fang)向， K3是(shi)阻(zu)(zu)(zu)(zu)尼(ni)開關(guan)，將它(ta)合上就(jiu)(jiu)可以將檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)短路，檢(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)(ji)的(de)(de)(de)(de)動(dong)(dong)(dong)圈(quan)(quan)就(jiu)(jiu)停止振(zhen)動(dong)(dong)(dong)。
其(qi)結構(gou)(圖1) 和(he)工(gong)作原(yuan)理與磁(ci)(ci)電(dian)(dian)(dian)系電(dian)(dian)(dian)表基本相(xiang)同。作為檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)，要(yao)求有較高(gao)的(de)(de)靈敏(min)(min)度(du)(du)，主要(yao)是電(dian)(dian)(dian)壓靈敏(min)(min)度(du)(du)和(he)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)靈敏(min)(min)度(du)(du)。為提高(gao)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)靈敏(min)(min)度(du)(du)，通(tong)常(chang)要(yao)增(zeng)加(jia)轉動(dong)(dong)(dong)力(li)(li)矩(ju)，例如加(jia)強磁(ci)(ci)場(chang)(chang)和(he)增(zeng)加(jia)動(dong)(dong)(dong)圈(quan)匝數。但限于氣隙(xi)(xi)尺寸(cun)，須(xu)(xu)用(yong)(yong)很(hen)細的(de)(de)導線繞制(zhi)動(dong)(dong)(dong)圈(quan)。因此電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)靈敏(min)(min)度(du)(du)高(gao)的(de)(de)檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)的(de)(de)動(dong)(dong)(dong)圈(quan)電(dian)(dian)(dian)阻(zu)(內阻(zu))較高(gao)。此外(wai)(wai)，要(yao)降(jiang)低反(fan)抗力(li)(li)矩(ju)，可采用(yong)(yong)力(li)(li)矩(ju)很(hen)弱(ruo)的(de)(de)拉絲（或懸(xuan)絲）將(jiang)動(dong)(dong)(dong)圈(quan)安置在(zai)永磁(ci)(ci)鐵的(de)(de)氣隙(xi)(xi)中。為此，檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)使(shi)用(yong)(yong)時(shi)要(yao)保(bao)(bao)持水平位置。檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)動(dong)(dong)(dong)圈(quan)沒有金(jin)屬框(kuang)架，阻(zu)尼(ni)力(li)(li)矩(ju)由動(dong)(dong)(dong)圈(quan)本身提供,動(dong)(dong)(dong)圈(quan)在(zai)氣隙(xi)(xi)磁(ci)(ci)場(chang)(chang)中運(yun)動(dong)(dong)(dong)時(shi),切割磁(ci)(ci)通(tong)而(er)產生電(dian)(dian)(dian)動(dong)(dong)(dong)勢(shi)，此電(dian)(dian)(dian)動(dong)(dong)(dong)勢(shi)引起的(de)(de)流(liu)(liu)(liu)(liu)(liu)過動(dong)(dong)(dong)圈(quan)和(he)外(wai)(wai)電(dian)(dian)(dian)路(lu)的(de)(de)電(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)，在(zai)檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)中又與磁(ci)(ci)場(chang)(chang)作用(yong)(yong)產生阻(zu)尼(ni)力(li)(li)矩(ju)。因此，外(wai)(wai)電(dian)(dian)(dian)路(lu)的(de)(de)結構(gou)要(yao)影響(xiang)檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)阻(zu)尼(ni)的(de)(de)強弱(ruo)。若(ruo)使(shi)檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)指示迅速達到穩(wen)定，應(ying)令(ling)其(qi)工(gong)作在(zai)稍欠阻(zu)尼(ni)狀態(tai)。磁(ci)(ci)電(dian)(dian)(dian)系檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)是很(hen)精(jing)細的(de)(de)電(dian)(dian)(dian)表，不使(shi)用(yong)(yong)時(shi)，須(xu)(xu)將(jiang)兩(liang)端短路(lu)，這(zhe)時(shi)阻(zu)尼(ni)強，可保(bao)(bao)護檢(jian)(jian)(jian)(jian)流(liu)(liu)(liu)(liu)(liu)計(ji)可動(dong)(dong)(dong)部(bu)分少受損害。
檢流計刻(ke)度盤上的刻(ke)度分(fen)格(ge)是均勻的，零點標在度盤中(zhong)心。動圈左右(you)偏(pian)轉，都(dou)可(ke)讀數。刻(ke)度上雖(sui)然標有數值，只是表示分(fen)格(ge)數；用于測(ce)電流、電壓(ya)時，要另(ling)行標定(ding)刻(ke)度分(fen)格(ge)所代表的準確數值。
磁(ci)電(dian)(dian)(dian)系檢流(liu)(liu)計(ji)(ji)的電(dian)(dian)(dian)流(liu)(liu)靈敏(min)度(du)以電(dian)(dian)(dian)流(liu)(liu)常數(shu)（電(dian)(dian)(dian)流(liu)(liu)靈敏(min)度(du)與電(dian)(dian)(dian)流(liu)(liu)常數(shu)互為倒數(shu)）表示，可達10-9安(an)/分格或更(geng)高，內阻(zu)(zu)達幾千歐。用檢流(liu)(liu)計(ji)(ji)測(ce)微(wei)弱電(dian)(dian)(dian)壓(ya)時(shi)，要(yao)(yao)求(qiu)有較(jiao)高的電(dian)(dian)(dian)壓(ya)靈敏(min)度(du)。因(yin)檢流(liu)(liu)計(ji)(ji)測(ce)量的基(ji)本(ben)量是電(dian)(dian)(dian)流(liu)(liu)，如(ru)要(yao)(yao)求(qiu)在一定的被測(ce)電(dian)(dian)(dian)壓(ya)下能有較(jiao)大的電(dian)(dian)(dian)流(liu)(liu)通過檢流(liu)(liu)計(ji)(ji)，則希望檢流(liu)(liu)計(ji)(ji)有較(jiao)低(di)內阻(zu)(zu)，但此時(shi)電(dian)(dian)(dian)流(liu)(liu)的靈敏(min)度(du)降低(di)。因(yin)此，電(dian)(dian)(dian)壓(ya)靈敏(min)度(du)高的檢流(liu)(liu)計(ji)(ji),其電(dian)(dian)(dian)流(liu)(liu)靈敏(min)度(du)要(yao)(yao)低(di)些(xie)（例如(ru)10-7安(an)/分格）。
為使用(yong)(yong)方便，可將磁電系(xi)檢流計(ji)做成便攜(xie)式，動(dong)圈用(yong)(yong)張絲拉(la)緊，并(bing)采(cai)用(yong)(yong)光線多次反射以提高靈敏度。
光(guang)電(dian)放大(da)式檢(jian)(jian)流(liu)(liu)(liu)計 　將光(guang)電(dian)放大(da)器與兩個(ge)磁電(dian)系檢(jian)(jian)流(liu)(liu)(liu)計結合(he)在一起即構成圖2所示的(de)光(guang)電(dian)放大(da)式檢(jian)(jian)流(liu)(liu)(liu)計。初級(ji)檢(jian)(jian)流(liu)(liu)(liu)計接在被測回路(lu)中，它(ta)的(de)小鏡(jing)將光(guang)線反射(she)到差分光(guang)電(dian)池上。兩光(guang)電(dian)池的(de)輸出(chu)電(dian)流(liu)(liu)(liu)之差流(liu)(liu)(liu)入次級(ji)檢(jian)(jian)流(liu)(liu)(liu)計G2。如此可獲得較強(qiang)的(de)信號。為使檢(jian)(jian)流(liu)(liu)(liu)計工作(zuo)穩定(ding)，通常采(cai)用負反饋(kui)線路(lu)。
測(ce)短(duan)暫(zan)脈(mo)沖(chong)(chong)電(dian)流(liu)所(suo)含電(dian)荷(he)(he)量的(de)磁(ci)電(dian)系檢(jian)流(liu)計(ji)(ji)(ji)(ji)。其(qi)(qi)(qi)可(ke)(ke)(ke)(ke)(ke)動(dong)部分(fen)(fen)(fen)具有較大(da)慣(guan)(guan)量。為保(bao)證(zheng)測(ce)量準確度，理論上(shang)要求在短(duan)暫(zan)脈(mo)沖(chong)(chong)電(dian)流(liu)通(tong)(tong)過檢(jian)流(liu)計(ji)(ji)(ji)(ji)時(shi)，可(ke)(ke)(ke)(ke)(ke)動(dong)部分(fen)(fen)(fen)應靜止不(bu)動(dong)；短(duan)暫(zan)脈(mo)沖(chong)(chong)消(xiao)失后(hou)，可(ke)(ke)(ke)(ke)(ke)動(dong)部分(fen)(fen)(fen)或(huo)(huo)單方向，或(huo)(huo)以刻度零點(dian)為中心作衰減擺動(dong)。不(bu)論哪種情(qing)況，取大(da)偏(pian)轉或(huo)(huo)擺動(dong)的(de)第一(yi)(yi)次大(da)值αm來表(biao)示電(dian)荷(he)(he)量Q的(de)大(da)小(xiao)，即(ji)αm=S,Sq是沖(chong)(chong)擊(ji)檢(jian)流(liu)計(ji)(ji)(ji)(ji)的(de)沖(chong)(chong)擊(ji)靈(ling)敏度。可(ke)(ke)(ke)(ke)(ke)通(tong)(tong)過接入光(guang)電(dian)放大(da)器(qi)來提(ti)高(gao)沖(chong)(chong)擊(ji)檢(jian)流(liu)計(ji)(ji)(ji)(ji)的(de)Sq。普通(tong)(tong)磁(ci)電(dian)系檢(jian)流(liu)計(ji)(ji)(ji)(ji)也可(ke)(ke)(ke)(ke)(ke)用(yong)以測(ce)電(dian)荷(he)(he)量，但(dan)其(qi)(qi)(qi)可(ke)(ke)(ke)(ke)(ke)動(dong)部分(fen)(fen)(fen)的(de)慣(guan)(guan)量不(bu)夠大(da)，會(hui)產生測(ce)量誤差。一(yi)(yi)種動(dong)磁(ci)鐵式檢(jian)流(liu)計(ji)(ji)(ji)(ji)。可(ke)(ke)(ke)(ke)(ke)動(dong)部分(fen)(fen)(fen)由(you)小(xiao)塊永磁(ci)鐵和小(xiao)鏡構成(cheng)(cheng)，其(qi)(qi)(qi)上(shang)下被張絲(si)拉(la)緊。小(xiao)磁(ci)鐵處于用(yong)疊片(pian)組成(cheng)(cheng)的(de)磁(ci)極間，磁(ci)極上(shang)繞有線圈，被檢(jian)測(ce)電(dian)流(liu)i通(tong)(tong)入此線圈后(hou),由(you)于可(ke)(ke)(ke)(ke)(ke)動(dong)部分(fen)(fen)(fen)的(de)質量和慣(guan)(guan)性都較小(xiao)，因此,可(ke)(ke)(ke)(ke)(ke)動(dong)部分(fen)(fen)(fen)可(ke)(ke)(ke)(ke)(ke)跟隨電(dian)流(liu)i引起的(de)交變磁(ci)場的(de)瞬時(shi)值的(de)變化動(dong)作。小(xiao)鏡左右擺動(dong)，光(guang)線被小(xiao)鏡反(fan)射后(hou),在標尺上(shang)形成(cheng)(cheng)光(guang)帶。i為零時(shi),小(xiao)鏡不(bu)動(dong),光(guang)帶縮成(cheng)(cheng)一(yi)(yi)條線。??為(wei)使(shi)振動檢流計的靈敏度(du)達(da)到高點，其可動部(bu)分的機械振動頻率應與外加(jia)電流頻率產生諧振。為(wei)此設置了另一套為(wei)調諧用的永磁系統，它包括磁軛(e)和一可旋動(dong)的永磁鐵。旋動(dong)永(yong)磁(ci)(ci)鐵可改變(bian)調(diao)諧系統磁(ci)(ci)軛的磁(ci)(ci)*度，即可改變(bian)與可動(dong)部(bu)分(fen)(fen)小(xiao)磁(ci)(ci)鐵間的吸力。這(zhe)等(deng)效(xiao)于(yu)調(diao)整(zheng)了(le)可動(dong)部(bu)分(fen)(fen)中張絲的拉力，因(yin)此改變(bian)了(le)可動(dong)部(bu)分(fen)(fen)的機械諧振頻率。這種(zhong)檢流計主要用(yong)于工頻，作指零儀表。
????WEIGEL安培表PQ72K 0-20MA

WEIGEL備件A1U2.2 13 4 0.5 H1
WEIGEL電流表0-50mA電流表 50VCATIII
WEIGEL備件674.110.00 EQ48K Sonder-MB: 0-250/500 mA Skala: 0-250/500 mA
WEIGEL備件(jian)DGW2.0
WEIGEL舵機計(ji)時器TYPE:BG40.×7/3121×0 SERIAL NO.:10T50 0508
WEIGEL分流器(qi)0.5 250A 60mV Q
WEIGEL電(dian)流(liu)表EQ96K-500V 96*96
WEIGEL壓(ya)力(li)變送器TYPE:V1U 2.2 SN:26057009
WEIGEL電流表EQ96-X 150/1 0-150A/750A
WEIGEL備(bei)件AU2.0 0-5A/0-20mA
WEIGEL電流變送(song)器電流變送(song)器/A1U2.0
WEIGEL表100V
WEIGEL壓力表EQ96K500V
WEIGEL油缸(gang)行程顯示器DAS10-40PIR S-Nr:943614008 備注645.4024.1000
WEIGEL電流表EQ144K/1A/20A 
WEIGEL電(dian)流表TYPe:PQ Y24 MB 0-20MA 200% 輸入電(dian)壓:24V DC
WEIGEL電(dian)流表EQ96K-300/1A 96*96
WEIGEL電器(qi)件AU2.0 105H0
WEIGEL電流顯示表PQ96K60-0-60mV DC本體型規(gui):PQ96K
WEIGEL備(bei)件EQ72-X 5A 5/10A
WEIGEL電(dian)流轉換器AUE2.2 0-1A 4-20mA
WEIGELmeter with movingLSP48-4-20MA DC current
WEIGEL分流器1000A/60MV
WEIGEL電器件SHUNT 4000A/60MV/CLASS 0.5
WEIGEL備(bei)件652.01.121600 SUS-01 R/G 220V DC
WEIGEL電壓表EQ96K-500V
WEIGEL電流表EQ48 150/5A
WEIGEL壓力表4-20mA(PRE[P.)
WEIGEL分流器SHUNT 60MV 800A， 137-9052
WEIGEL行(xing)程顯示器DAS10-NS40/P1R-06
WEIGEL電流表EQ96K 300/1
WEIGEL電流表EQ48 10A
WEIGEL電流表EQ 72K N/1A AC
WEIGEL變送器PTU2.OS 17 26 41 H3
WEIGEL表P72PRS
WEIGEL備件(jian)AU2.0 Input: 0...5A Output: 0...20mA
WEIGEL備件EQ72K
WEIGEL分流器SHUNT 60MV 500A KL 0.5 DIN43703， 137-9064
WEIGEL電流表Q96K5A(10)400/5A
WEIGEL電流表EQ 72K
WEIGEL橫式指針(zhen)表(biao)MP48X24K 4~20mA 24mm×48mm 橫式指針(zhen)表(biao)
WEIGEL備件(jian)652.02.121600 SUS-01-Q R/G 220V DC
WEIGEL分(fen)流器869.7330.1 50KA/250ms
WEIGEL電(dian)流表(biao)EQ96-X 3000/1A
WEIGEL備件EQ48-MESSB:25A-SKALA:0-25A+STTX*
WEIGEL電流(liu)表EQ 72E
WEIGEL分流器SHUNT 18000A/200MV/CLASS 0.5
WEIGEL直流電壓表(biao)PQ72k
WEIGEL備件PQ48K CA
WEIGEL電流表EQ72 0-100/5A
WEIGEL電壓變送器V1U2.2 input AC cl.0.5
WEIGEL豎(shu)式指(zhi)針(zhen)表(biao)MP48X24K 4~20mA 24mm×48mm豎(shu)式指(zhi)針(zhen)表(biao)
WEIGEL電流表(biao)RW96MIN/MAX 0-1A 230V AC
WEIGEL備件EQ72K 100/5A 600V
WEIGEL電(dian)器件SHUNT 1500A/60MV/CLASS 0.5
WEIGEL電流(liu)表PQ72K 0-10V
WEIGEL橫(heng)式(shi)指(zhi)針表MP48X96K(4~20mA 帶零位調整）96mm×48mm橫(heng)式(shi)指(zhi)針表
WEIGEL表(biao)DA12-NA40/F10R 72*24
WEIGEL備件EQ48-MESSB:10A-SKALA:0-10A+STTX*
WEIGEL電壓表PQ96K 0-10V 0-120% POTI (0-10VDC/1mA + scale 0-120% w.pot )
WEIGEL備(bei)件EQ72K 50/5A 600V
WEIGEL電流表PQ96K 0-6000A
WEIGEL滑差表(biao)SY96S 100V 50HZ WITH FULLSIZED REAR COVER
WEIGEL電流表PQ72K 0-100A 4-20mA
WEIGEL電流表AMEQ72KLZS001 150/300/1A
WEIGEL分流器KL0.5 2000Amp/150mV
WEIGEL電流負載表PQ72K 10V 120%
WEIGEL電(dian)流表EQ144K/1A/40A
WEIGEL電流表PQ72K 0-100A 4-20MA
WEIGEL恒張力指示INDICATORPQ42K Beleuchtung:24V、12V、6V
WEIGEL備件EQ96K 0-500V
WEIGEL電壓(ya)表EQ96K 100/120V 0-20/24kV
WEIGEL分(fen)流器FLQ1017B2-300A
WEIGEL分流器4000A/60MV
WEIGEL交流電壓變送器VIU2.2
WEIGEL電壓表EQ72K 0~750V
WEIGEL速度(du)表LSSM3 4...20mA 0...8rpm
WEIGEL分流(liu)器額定電流(liu)50A 直流(liu)輸出要60mV 可以(yi)短時耐受(shou)5倍的(de)過流(liu)
WEIGEL電流表PQ96K 4-20mA:=0-250V
WEIGEL備件(jian)PQ 96
WEIGEL電流表(biao)PQ96K 10V 0-8000
WEIGEL備件EQ96K 0-1A =》0-1600A
WEIGEL表UH230V 48-62HZ max.1.2VA
WEIGEL分流器安(an)裝盤SHUNTISO. PLATE LARGE 155X90X6MM TRAFO，870-93260
WEIGEL表(biao)150v
WEIGEL電流表EQ96-X 100/1 0-100A/500A
WEIGEL數字顯示器DAS10-40P1R S-NR:942882-008
WEIGEL顯示器DAS10-40PIR S-Nr.943614008
WEIGEL電流表AMPQ72KDZS012
WEIGEL橫式(shi)指針表MP96X24K(4~20mA 帶零位(wei)調整） 96mm×24mm
WEIGEL備件WQ96/2S MB/RANGE 0-150 AC 300V CAT III
WEIGEL動鐵(tie)式儀(yi)表AC 0..600A （Moving-iron meter AC 0..600 A ）
WEIGEL備件LSP48CA
檢(jian)流(liu)(liu)計(ji)是(shi)(shi)(shi)(shi)磁(ci)電(dian)(dian)(dian)(dian)式儀(yi)(yi)表(biao)，它(ta)(ta)是(shi)(shi)(shi)(shi)根據載流(liu)(liu)線(xian)(xian)圈(quan)(quan)(quan)在(zai)磁(ci)場(chang)中受(shou)到(dao)(dao)(dao)(dao)(dao)力矩而(er)偏(pian)(pian)轉(zhuan)(zhuan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)原理(li)制(zhi)成(cheng)的(de)(de)(de)(de)(de)(de)(de)(de)(de)。普(pu)通(tong)電(dian)(dian)(dian)(dian)表(biao)中線(xian)(xian)圈(quan)(quan)(quan)是(shi)(shi)(shi)(shi)安放(fang)在(zai)軸(zhou)承上，用(yong)彈簧游絲來維持平衡，用(yong)指針來指示偏(pian)(pian)轉(zhuan)(zhuan)。由于軸(zhou)承有摩擦，被測電(dian)(dian)(dian)(dian)流(liu)(liu)不能(neng)太弱(ruo)。檢(jian)流(liu)(liu)計(ji)使用(yong)極細的(de)(de)(de)(de)(de)(de)(de)(de)(de)金屬(shu)懸絲代替(ti)軸(zhou)承懸掛(gua)在(zai)磁(ci)場(chang)中，由于懸絲細而(er)長(chang)(chang)，反(fan)抗力矩很小(xiao)(xiao)(xiao)，所(suo)以(yi)(yi)(yi)(yi)有很弱(ruo)的(de)(de)(de)(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)通(tong)過線(xian)(xian)圈(quan)(quan)(quan)就(jiu)足以(yi)(yi)(yi)(yi)使它(ta)(ta)產生(sheng)顯著(zhu)的(de)(de)(de)(de)(de)(de)(de)(de)(de)偏(pian)(pian)轉(zhuan)(zhuan)。因(yin)(yin)而(er)檢(jian)流(liu)(liu)計(ji)比一(yi)般(ban)的(de)(de)(de)(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)表(biao)靈敏(min)的(de)(de)(de)(de)(de)(de)(de)(de)(de)多，可(ke)(ke)以(yi)(yi)(yi)(yi)測量(liang)微電(dian)(dian)(dian)(dian)流(liu)(liu)（10-7~10-10A）或者(zhe)微電(dian)(dian)(dian)(dian)壓(ya)(ya)（10-3~10-6V），如光(guang)電(dian)(dian)(dian)(dian)流(liu)(liu)、生(sheng)理(li)電(dian)(dian)(dian)(dian)流(liu)(liu)、溫差電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)勢等。*記錄神(shen)經動(dong)(dong)(dong)作(zuo)電(dian)(dian)(dian)(dian)位(wei)(wei)，就(jiu)是(shi)(shi)(shi)(shi)用(yong)此(ci)(ci)(ci)類(lei)儀(yi)(yi)器實現的(de)(de)(de)(de)(de)(de)(de)(de)(de)。以(yi)(yi)(yi)(yi)光(guang)點式檢(jian)流(liu)(liu)計(ji)為(wei)例(li)，檢(jian)流(liu)(liu)計(ji)由三(san)部(bu)(bu)分(fen)組成(cheng)：(1)磁(ci)場(chang)部(bu)(bu)分(fen)：由永磁(ci)鐵(N,S)產生(sheng)磁(ci)場(chang)，圓(yuan)柱形軟(ruan)鐵心(xin)(J)使氣隙(xi)中磁(ci)場(chang)呈(cheng)均勻輻射(she)狀(zhuang)(zhuang)。(2)偏(pian)(pian)轉(zhuan)(zhuan)部(bu)(bu)分(fen)：能(neng)在(zai)氣隙(xi)中轉(zhuan)(zhuan)動(dong)(dong)(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)矩形線(xian)(xian)圈(quan)(quan)(quan)C及從上下拉緊線(xian)(xian)圈(quan)(quan)(quan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)金屬(shu)張絲E,只要有很小(xiao)(xiao)(xiao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)力矩作(zuo)用(yong)，就(jiu)能(neng)使線(xian)(xian)圈(quan)(quan)(quan)偏(pian)(pian)轉(zhuan)(zhuan)。(3)讀數部(bu)(bu)分(fen)：小(xiao)(xiao)(xiao)鏡(jing)(jing)M固(gu)定在(zai)動(dong)(dong)(dong)圈(quan)(quan)(quan)上，它(ta)(ta)把光(guang)源射(she)進來的(de)(de)(de)(de)(de)(de)(de)(de)(de)光(guang)束反(fan)射(she)到(dao)(dao)(dao)(dao)(dao)標尺(chi)(chi)上形成(cheng)一(yi)個光(guang)標，當電(dian)(dian)(dian)(dian)流(liu)(liu)流(liu)(liu)過動(dong)(dong)(dong)圈(quan)(quan)(quan)時(shi)，動(dong)(dong)(dong)圈(quan)(quan)(quan)受(shou)力偏(pian)(pian)轉(zhuan)(zhuan)而(er)帶動(dong)(dong)(dong)小(xiao)(xiao)(xiao)鏡(jing)(jing)M轉(zhuan)(zhuan)過?角，因(yin)(yin)而(er)反(fan)射(she)光(guang)束偏(pian)(pian)轉(zhuan)(zhuan)的(de)(de)(de)(de)(de)(de)(de)(de)(de)角度為(wei),光(guang)標在(zai)標尺(chi)(chi)上移動(dong)(dong)(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)距(ju)(ju)離n=L*α，L為(wei)小(xiao)(xiao)(xiao)鏡(jing)(jing)到(dao)(dao)(dao)(dao)(dao)標尺(chi)(chi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)距(ju)(ju)離，實際(ji)上阻(zu)尼(ni)總(zong)是(shi)(shi)(shi)(shi)存在(zai)的(de)(de)(de)(de)(de)(de)(de)(de)(de),當R≠∞,D≠0時(shi)有三(san)種運(yun)動(dong)(dong)(dong)狀(zhuang)(zhuang)態(tai).1)欠阻(zu)尼(ni)狀(zhuang)(zhuang)態(tai):此(ci)(ci)(ci)時(shi)外(wai)電(dian)(dian)(dian)(dian)阻(zu)R較(jiao)大，β<ω,動(dong)(dong)(dong)圈(quan)(quan)(quan)以(yi)(yi)(yi)(yi)平衡位(wei)(wei)置(zhi)(zhi)為(wei)中心(xin)作(zuo)衰(shuai)減振(zhen)動(dong)(dong)(dong)，并且(qie)逐漸(jian)趨緊于平衡位(wei)(wei)置(zhi)(zhi)。2)臨(lin)界阻(zu)尼(ni)狀(zhuang)(zhuang)態(tai):R=Rc,β=ω,動(dong)(dong)(dong)圈(quan)(quan)(quan)無振(zhen)動(dong)(dong)(dong)的(de)(de)(de)(de)(de)(de)(de)(de)(de)很快達(da)到(dao)(dao)(dao)(dao)(dao)平衡位(wei)(wei)置(zhi)(zhi)，此(ci)(ci)(ci)時(shi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)外(wai)電(dian)(dian)(dian)(dian)阻(zu)稱為(wei)臨(lin)界電(dian)(dian)(dian)(dian)阻(zu)Rc，一(yi)般(ban)來說，檢(jian)流(liu)(liu)計(ji)的(de)(de)(de)(de)(de)(de)(de)(de)(de)臨(lin)界阻(zu)尼(ni)狀(zhuang)(zhuang)態(tai)是(shi)(shi)(shi)(shi)它(ta)(ta)的(de)(de)(de)(de)(de)(de)(de)(de)(de)理(li)想工作(zuo)狀(zhuang)(zhuang)態(tai)。3)過阻(zu)尼(ni)狀(zhuang)(zhuang)態(tai):當β>ω,即R<Rc,此(ci)(ci)(ci)時(shi)動(dong)(dong)(dong)圈(quan)(quan)(quan)也是(shi)(shi)(shi)(shi)做單(dan)向(xiang)偏(pian)(pian)轉(zhuan)(zhuan)運(yun)動(dong)(dong)(dong)，緩(huan)慢的(de)(de)(de)(de)(de)(de)(de)(de)(de)趨向(xiang)平衡位(wei)(wei)置(zhi)(zhi)。R越小(xiao)(xiao)(xiao)，到(dao)(dao)(dao)(dao)(dao)達(da)平衡位(wei)(wei)置(zhi)(zhi)的(de)(de)(de)(de)(de)(de)(de)(de)(de)時(shi)間(jian)越長(chang)(chang)。因(yin)(yin)為(wei)過阻(zu)尼(ni)運(yun)動(dong)(dong)(dong)中，動(dong)(dong)(dong)圈(quan)(quan)(quan)到(dao)(dao)(dao)(dao)(dao)達(da)平衡的(de)(de)(de)(de)(de)(de)(de)(de)(de)時(shi)間(jian)長(chang)(chang)，而(er)且(qie)不易判斷動(dong)(dong)(dong)圈(quan)(quan)(quan)是(shi)(shi)(shi)(shi)否到(dao)(dao)(dao)(dao)(dao)達(da)平衡位(wei)(wei)置(zhi)(zhi)，因(yin)(yin)此(ci)(ci)(ci)它(ta)(ta)對于測量(liang)是(shi)(shi)(shi)(shi)不利的(de)(de)(de)(de)(de)(de)(de)(de)(de)。由于檢(jian)流(liu)(liu)計(ji)很靈敏(min)，一(yi)般(ban)通(tong)過電(dian)(dian)(dian)(dian)流(liu)(liu)不能(neng)超過1μA。電(dian)(dian)(dian)(dian)壓(ya)(ya)經過兩次分(fen)壓(ya)(ya)后得到(dao)(dao)(dao)(dao)(dao)很小(xiao)(xiao)(xiao)的(de)(de)(de)(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(常(chang)小(xiao)(xiao)(xiao)于1mV)后才(cai)加到(dao)(dao)(dao)(dao)(dao)檢(jian)流(liu)(liu)計(ji)電(dian)(dian)(dian)(dian)路(lu)中。第(di)一(yi)次采用(yong)滑線(xian)(xian)變阻(zu)器分(fen)壓(ya)(ya)，第(di)二次采用(yong)固(gu)定電(dian)(dian)(dian)(dian)阻(zu)R1/R0?≈10-3~10-4的(de)(de)(de)(de)(de)(de)(de)(de)(de)數量(liang)級分(fen)壓(ya)(ya)。K2是(shi)(shi)(shi)(shi)換向(xiang)開(kai)(kai)關，用(yong)它(ta)(ta)可(ke)(ke)以(yi)(yi)(yi)(yi)變換過檢(jian)流(liu)(liu)計(ji)的(de)(de)(de)(de)(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)方向(xiang)， K3是(shi)(shi)(shi)(shi)阻(zu)尼(ni)開(kai)(kai)關，將它(ta)(ta)合上就(jiu)可(ke)(ke)以(yi)(yi)(yi)(yi)將檢(jian)流(liu)(liu)計(ji)短路(lu)，檢(jian)流(liu)(liu)計(ji)的(de)(de)(de)(de)(de)(de)(de)(de)(de)動(dong)(dong)(dong)圈(quan)(quan)(quan)就(jiu)停止振(zhen)動(dong)(dong)(dong)。
其結構(圖1) 和(he)工作原理與磁電(dian)(dian)(dian)(dian)系電(dian)(dian)(dian)(dian)表(biao)基本相同。作為(wei)檢(jian)流(liu)(liu)計(ji)(ji)(ji)，要(yao)求有(you)較高的(de)(de)(de)靈(ling)敏度(du)，主要(yao)是(shi)電(dian)(dian)(dian)(dian)壓靈(ling)敏度(du)和(he)電(dian)(dian)(dian)(dian)流(liu)(liu)靈(ling)敏度(du)。為(wei)提(ti)高電(dian)(dian)(dian)(dian)流(liu)(liu)靈(ling)敏度(du)，通常要(yao)增加(jia)(jia)轉動(dong)(dong)(dong)力(li)矩(ju)(ju)，例如加(jia)(jia)強磁場和(he)增加(jia)(jia)動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)匝數。但(dan)限于氣隙(xi)尺寸(cun)，須用(yong)很(hen)細的(de)(de)(de)導線繞(rao)制動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)。因此(ci)電(dian)(dian)(dian)(dian)流(liu)(liu)靈(ling)敏度(du)高的(de)(de)(de)檢(jian)流(liu)(liu)計(ji)(ji)(ji)的(de)(de)(de)動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)電(dian)(dian)(dian)(dian)阻(內阻)較高。此(ci)外，要(yao)降低反(fan)抗力(li)矩(ju)(ju)，可采用(yong)力(li)矩(ju)(ju)很(hen)弱的(de)(de)(de)拉(la)絲（或懸絲）將動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)安置在(zai)永磁鐵的(de)(de)(de)氣隙(xi)中(zhong)。為(wei)此(ci)，檢(jian)流(liu)(liu)計(ji)(ji)(ji)使用(yong)時(shi)(shi)要(yao)保(bao)持水平位置。檢(jian)流(liu)(liu)計(ji)(ji)(ji)動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)沒有(you)金屬框(kuang)架，阻尼(ni)(ni)力(li)矩(ju)(ju)由動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)本身提(ti)供(gong),動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)在(zai)氣隙(xi)磁場中(zhong)運動(dong)(dong)(dong)時(shi)(shi),切割磁通而產(chan)(chan)生(sheng)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)勢，此(ci)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)勢引起(qi)的(de)(de)(de)流(liu)(liu)過動(dong)(dong)(dong)圈(quan)(quan)(quan)(quan)和(he)外電(dian)(dian)(dian)(dian)路(lu)的(de)(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)，在(zai)檢(jian)流(liu)(liu)計(ji)(ji)(ji)中(zhong)又(you)與磁場作用(yong)產(chan)(chan)生(sheng)阻尼(ni)(ni)力(li)矩(ju)(ju)。因此(ci)，外電(dian)(dian)(dian)(dian)路(lu)的(de)(de)(de)結構要(yao)影(ying)響檢(jian)流(liu)(liu)計(ji)(ji)(ji)阻尼(ni)(ni)的(de)(de)(de)強弱。若使檢(jian)流(liu)(liu)計(ji)(ji)(ji)指示迅速達到穩定，應令其工作在(zai)稍欠(qian)阻尼(ni)(ni)狀態。磁電(dian)(dian)(dian)(dian)系檢(jian)流(liu)(liu)計(ji)(ji)(ji)是(shi)很(hen)精細的(de)(de)(de)電(dian)(dian)(dian)(dian)表(biao)，不使用(yong)時(shi)(shi)，須將兩端短路(lu)，這時(shi)(shi)阻尼(ni)(ni)強，可保(bao)護(hu)檢(jian)流(liu)(liu)計(ji)(ji)(ji)可動(dong)(dong)(dong)部分少受(shou)損害。
檢流計刻度盤(pan)上的刻度分格(ge)是均勻(yun)的，零點標(biao)在(zai)度盤(pan)中心。動圈左右偏轉，都可讀數。刻度上雖然標(biao)有數值，只是表示分格(ge)數；用于測電(dian)流、電(dian)壓時，要另行標(biao)定刻度分格(ge)所代表的準確數值。
磁電(dian)(dian)(dian)(dian)系(xi)檢(jian)(jian)流(liu)(liu)計的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)靈(ling)(ling)敏(min)度(du)以電(dian)(dian)(dian)(dian)流(liu)(liu)常數（電(dian)(dian)(dian)(dian)流(liu)(liu)靈(ling)(ling)敏(min)度(du)與(yu)電(dian)(dian)(dian)(dian)流(liu)(liu)常數互為(wei)倒數）表示，可達(da)10-9安/分格或更高(gao)(gao)，內阻達(da)幾千(qian)歐(ou)。用檢(jian)(jian)流(liu)(liu)計測(ce)微弱電(dian)(dian)(dian)(dian)壓時，要(yao)求有較高(gao)(gao)的(de)(de)電(dian)(dian)(dian)(dian)壓靈(ling)(ling)敏(min)度(du)。因(yin)檢(jian)(jian)流(liu)(liu)計測(ce)量(liang)的(de)(de)基(ji)本量(liang)是電(dian)(dian)(dian)(dian)流(liu)(liu)，如(ru)要(yao)求在一定的(de)(de)被測(ce)電(dian)(dian)(dian)(dian)壓下能有較大的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)通過檢(jian)(jian)流(liu)(liu)計，則希(xi)望檢(jian)(jian)流(liu)(liu)計有較低(di)內阻，但此(ci)時電(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)靈(ling)(ling)敏(min)度(du)降低(di)。因(yin)此(ci)，電(dian)(dian)(dian)(dian)壓靈(ling)(ling)敏(min)度(du)高(gao)(gao)的(de)(de)檢(jian)(jian)流(liu)(liu)計,其電(dian)(dian)(dian)(dian)流(liu)(liu)靈(ling)(ling)敏(min)度(du)要(yao)低(di)些（例如(ru)10-7安/分格）。
為(wei)使用(yong)方(fang)便，可將磁(ci)電(dian)系檢流計做成便攜式，動圈用(yong)張(zhang)絲拉緊，并采(cai)用(yong)光線(xian)多次反射以提高(gao)靈(ling)敏度。
光電放大(da)式檢流(liu)計(ji) 　將(jiang)光電放大(da)器與兩(liang)個(ge)磁電系檢流(liu)計(ji)結(jie)合在一起(qi)即構成圖2所示的光電放大(da)式檢流(liu)計(ji)。初級檢流(liu)計(ji)接在被(bei)測回路(lu)中，它的小鏡將(jiang)光線反射(she)到差分(fen)光電池上。兩(liang)光電池的輸出(chu)電流(liu)之(zhi)差流(liu)入次級檢流(liu)計(ji)G2。如此(ci)可(ke)獲得較強的信號。為(wei)使檢流(liu)計(ji)工作穩定，通常采用負反饋線路(lu)。
測(ce)(ce)(ce)短(duan)(duan)暫(zan)脈(mo)沖(chong)(chong)電流所含電荷(he)量(liang)(liang)(liang)的磁(ci)(ci)(ci)(ci)電系(xi)檢(jian)流計(ji)(ji)。其可(ke)(ke)(ke)動(dong)(dong)(dong)部分(fen)(fen)具有(you)較大(da)(da)慣(guan)量(liang)(liang)(liang)。為(wei)保證測(ce)(ce)(ce)量(liang)(liang)(liang)準確度(du)，理論(lun)上(shang)要(yao)求在短(duan)(duan)暫(zan)脈(mo)沖(chong)(chong)電流通過(guo)檢(jian)流計(ji)(ji)時(shi)(shi)，可(ke)(ke)(ke)動(dong)(dong)(dong)部分(fen)(fen)應(ying)靜止不(bu)動(dong)(dong)(dong)；短(duan)(duan)暫(zan)脈(mo)沖(chong)(chong)消失后(hou)，可(ke)(ke)(ke)動(dong)(dong)(dong)部分(fen)(fen)或(huo)(huo)單(dan)方向(xiang)，或(huo)(huo)以刻度(du)零點為(wei)中心作衰減擺(bai)(bai)動(dong)(dong)(dong)。不(bu)論(lun)哪(na)種(zhong)情況，取大(da)(da)偏轉或(huo)(huo)擺(bai)(bai)動(dong)(dong)(dong)的第(di)一(yi)次(ci)大(da)(da)值(zhi)αm來表示電荷(he)量(liang)(liang)(liang)Q的大(da)(da)小，即αm=S,Sq是沖(chong)(chong)擊(ji)檢(jian)流計(ji)(ji)的沖(chong)(chong)擊(ji)靈(ling)敏度(du)。可(ke)(ke)(ke)通過(guo)接入(ru)光(guang)(guang)(guang)電放大(da)(da)器來提高沖(chong)(chong)擊(ji)檢(jian)流計(ji)(ji)的Sq。普通磁(ci)(ci)(ci)(ci)電系(xi)檢(jian)流計(ji)(ji)也可(ke)(ke)(ke)用以測(ce)(ce)(ce)電荷(he)量(liang)(liang)(liang)，但(dan)其可(ke)(ke)(ke)動(dong)(dong)(dong)部分(fen)(fen)的慣(guan)量(liang)(liang)(liang)不(bu)夠大(da)(da)，會產生測(ce)(ce)(ce)量(liang)(liang)(liang)誤差(cha)。一(yi)種(zhong)動(dong)(dong)(dong)磁(ci)(ci)(ci)(ci)鐵式檢(jian)流計(ji)(ji)。可(ke)(ke)(ke)動(dong)(dong)(dong)部分(fen)(fen)由小塊永磁(ci)(ci)(ci)(ci)鐵和小鏡構成(cheng)(cheng)(cheng)，其上(shang)下(xia)被(bei)張絲拉(la)緊。小磁(ci)(ci)(ci)(ci)鐵處(chu)于用疊(die)片組成(cheng)(cheng)(cheng)的磁(ci)(ci)(ci)(ci)極間，磁(ci)(ci)(ci)(ci)極上(shang)繞有(you)線(xian)圈，被(bei)檢(jian)測(ce)(ce)(ce)電流i通入(ru)此(ci)線(xian)圈后(hou),由于可(ke)(ke)(ke)動(dong)(dong)(dong)部分(fen)(fen)的質量(liang)(liang)(liang)和慣(guan)性都較小，因此(ci),可(ke)(ke)(ke)動(dong)(dong)(dong)部分(fen)(fen)可(ke)(ke)(ke)跟隨電流i引起的交變磁(ci)(ci)(ci)(ci)場(chang)的瞬時(shi)(shi)值(zhi)的變化動(dong)(dong)(dong)作。小鏡左右擺(bai)(bai)動(dong)(dong)(dong)，光(guang)(guang)(guang)線(xian)被(bei)小鏡反射(she)后(hou),在標尺(chi)上(shang)形成(cheng)(cheng)(cheng)光(guang)(guang)(guang)帶(dai)。i為(wei)零時(shi)(shi),小鏡不(bu)動(dong)(dong)(dong),光(guang)(guang)(guang)帶(dai)縮(suo)成(cheng)(cheng)(cheng)一(yi)條線(xian)。??
????