【萬能表】萬能表的使用(yong)方法 電工用(yong)的萬能表的使用(yong)方法(fa)

一、指針表和數字表的選用：

1、指針表讀取精度較差，但指針擺動的過程比較直觀，其擺動速度幅度有時也能比較客觀地反映了被測量的大小（比如測電視機數據總線（SDL）在傳送數據時的輕微抖動）；數字表讀數直觀，但數字變化的過程看起來很雜亂，不太容易觀看。

2、指針表內一般有兩塊電池，一塊低電壓的1.5V，一塊是高電壓的9V或15V，其黑表筆相對紅表筆來說是正端。數字表則常用一塊6V或9V的電池。在電(dian)阻(zu)檔(dang)(dang)，指(zhi)針表的(de)(de)表筆輸出電(dian)流相對數字表來說要大很多(duo)，用R×1Ω檔(dang)(dang)可(ke)以(yi)使揚聲(sheng)器發(fa)出響亮(liang)(liang)的(de)(de)“噠(da)”聲(sheng)，用R×10kΩ檔(dang)(dang)甚至可(ke)以(yi)點亮(liang)(liang)發(fa)光二極(ji)管（LED）。

3、在電(dian)(dian)(dian)壓(ya)檔，指針表內阻相(xiang)對(dui)數字(zi)表來說比(bi)(bi)較小(xiao)，測(ce)(ce)量精度相(xiang)比(bi)(bi)較差。某些高(gao)電(dian)(dian)(dian)壓(ya)微電(dian)(dian)(dian)流的(de)(de)(de)(de)場合甚至(zhi)無(wu)法測(ce)(ce)準(zhun)，因為其內阻會對(dui)被(bei)(bei)測(ce)(ce)電(dian)(dian)(dian)路造成影響(xiang)（比(bi)(bi)如在測(ce)(ce)電(dian)(dian)(dian)視機顯(xian)像管的(de)(de)(de)(de)加速級(ji)電(dian)(dian)(dian)壓(ya)時(shi)測(ce)(ce)量值(zhi)會比(bi)(bi)實(shi)際值(zhi)低很(hen)(hen)多(duo)）。數字(zi)表電(dian)(dian)(dian)壓(ya)檔的(de)(de)(de)(de)內阻很(hen)(hen)大，至(zhi)少在兆歐(ou)級(ji)，對(dui)被(bei)(bei)測(ce)(ce)電(dian)(dian)(dian)路影響(xiang)很(hen)(hen)小(xiao)。但極高(gao)的(de)(de)(de)(de)輸出(chu)阻抗使其易受感應電(dian)(dian)(dian)壓(ya)的(de)(de)(de)(de)影響(xiang)，在一些電(dian)(dian)(dian)磁(ci)干擾比(bi)(bi)較強的(de)(de)(de)(de)場合測(ce)(ce)出(chu)的(de)(de)(de)(de)數據可能(neng)是虛的(de)(de)(de)(de)。

4、總之，在相對來(lai)說(shuo)大電(dian)流高電(dian)壓的模擬(ni)電(dian)路(lu)測量中適用指針(zhen)表，比如電(dian)視機(ji)、音響功放。在低電(dian)壓小(xiao)電(dian)流的數(shu)字(zi)電(dian)路(lu)測量中適用數(shu)字(zi)表，比如BP機(ji)、手(shou)機(ji)等。不(bu)是絕對的，可根據(ju)情況選用指針(zhen)表和數(shu)字(zi)表。

二、測量技巧（如不作說明，則指用的是指針表）：

1、測喇叭、耳機、動(dong)圈式話筒(tong)：用R×1Ω檔，任一(yi)表筆接(jie)一(yi)端，另一(yi)表筆點(dian)觸另一(yi)端，正常(chang)時會發(fa)出(chu)清脆響(xiang)(xiang)量的“噠”聲(sheng)。如果(guo)不響(xiang)(xiang)，則是線(xian)圈斷了，如果(guo)響(xiang)(xiang)聲(sheng)小而尖(jian)，則是有擦(ca)圈問題，也不能用。

2、測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)：用電(dian)(dian)(dian)(dian)(dian)(dian)阻檔(dang)(dang)，根據(ju)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)選(xuan)擇適當的(de)(de)量(liang)(liang)(liang)(liang)程，并注(zhu)意(yi)測(ce)(ce)(ce)量(liang)(liang)(liang)(liang)時對于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)解(jie)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)黑表筆要(yao)接電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)正(zheng)極。①、估測(ce)(ce)(ce)微(wei)波法級(ji)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)的(de)(de)大小：可(ke)(ke)憑經(jing)驗或(huo)參照相(xiang)(xiang)同(tong)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)的(de)(de)標準(zhun)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)，根據(ju)指針(zhen)擺(bai)動的(de)(de)最(zui)大幅(fu)度(du)來判定(ding)(ding)。所參照的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)不(bu)必耐壓(ya)值也一(yi)(yi)(yi)樣，只(zhi)(zhi)(zhi)要(yao)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)相(xiang)(xiang)同(tong)即(ji)可(ke)(ke)，例如(ru)(ru)估測(ce)(ce)(ce)一(yi)(yi)(yi)個100μF/250V的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)可(ke)(ke)用一(yi)(yi)(yi)個100μF/25V的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)來參照，只(zhi)(zhi)(zhi)要(yao)它們指針(zhen)擺(bai)動最(zui)大幅(fu)度(du)一(yi)(yi)(yi)樣，即(ji)可(ke)(ke)斷定(ding)(ding)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)一(yi)(yi)(yi)樣。②、估測(ce)(ce)(ce)皮法級(ji)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)大小：要(yao)用R×10kΩ檔(dang)(dang)，但(dan)只(zhi)(zhi)(zhi)能(neng)測(ce)(ce)(ce)到1000pF以(yi)上的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)。對1000pF或(huo)稍(shao)(shao)大一(yi)(yi)(yi)點的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)，只(zhi)(zhi)(zhi)要(yao)表針(zhen)稍(shao)(shao)有擺(bai)動，即(ji)可(ke)(ke)認為容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)夠了。③、測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)是否漏(lou)電(dian)(dian)(dian)(dian)(dian)(dian)：對一(yi)(yi)(yi)千微(wei)法以(yi)上的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)，可(ke)(ke)先用R×10Ω檔(dang)(dang)將其快速充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)，并初步估測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)量(liang)(liang)(liang)(liang)，然后改到R×1kΩ檔(dang)(dang)繼續(xu)測(ce)(ce)(ce)一(yi)(yi)(yi)會兒，這時指針(zhen)不(bu)應(ying)回返(fan)(fan)，而應(ying)停在或(huo)十(shi)分接近∞處(chu)，否則(ze)就(jiu)(jiu)是有漏(lou)電(dian)(dian)(dian)(dian)(dian)(dian)現(xian)象。對一(yi)(yi)(yi)些幾十(shi)微(wei)法以(yi)下的(de)(de)定(ding)(ding)時或(huo)振蕩電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)（比如(ru)(ru)彩(cai)電(dian)(dian)(dian)(dian)(dian)(dian)開關電(dian)(dian)(dian)(dian)(dian)(dian)源的(de)(de)振蕩電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)(rong)），對其漏(lou)電(dian)(dian)(dian)(dian)(dian)(dian)特(te)性要(yao)求非常高，只(zhi)(zhi)(zhi)要(yao)稍(shao)(shao)有漏(lou)電(dian)(dian)(dian)(dian)(dian)(dian)就(jiu)(jiu)不(bu)能(neng)用，這時可(ke)(ke)在R×1kΩ檔(dang)(dang)充(chong)完(wan)電(dian)(dian)(dian)(dian)(dian)(dian)后再(zai)改用R×10kΩ檔(dang)(dang)繼續(xu)測(ce)(ce)(ce)量(liang)(liang)(liang)(liang)，同(tong)樣表針(zhen)應(ying)停在∞處(chu)而不(bu)應(ying)回返(fan)(fan)。

3、在(zai)(zai)路(lu)測(ce)(ce)(ce)二(er)極(ji)管(guan)(guan)、三(san)極(ji)管(guan)(guan)、穩壓(ya)管(guan)(guan)好壞：因為在(zai)(zai)實(shi)際電(dian)(dian)路(lu)中，三(san)極(ji)管(guan)(guan)的(de)偏(pian)置電(dian)(dian)阻(zu)(zu)(zu)或(huo)二(er)極(ji)管(guan)(guan)、穩壓(ya)管(guan)(guan)的(de)周邊電(dian)(dian)阻(zu)(zu)(zu)一般都比(bi)較大(da)，大(da)都在(zai)(zai)幾百幾千歐姆以(yi)(yi)(yi)上，這樣，我們就(jiu)可(ke)(ke)(ke)以(yi)(yi)(yi)用(yong)萬用(yong)表的(de)R×10Ω或(huo)R×1Ω檔來在(zai)(zai)路(lu)測(ce)(ce)(ce)量PN結的(de)好壞。在(zai)(zai)路(lu)測(ce)(ce)(ce)量時(shi)(shi)，用(yong)R×10Ω檔測(ce)(ce)(ce)PN結應有較明(ming)顯(xian)的(de)正(zheng)(zheng)反(fan)向(xiang)特(te)性（如(ru)(ru)果正(zheng)(zheng)反(fan)向(xiang)電(dian)(dian)阻(zu)(zu)(zu)相差不(bu)太明(ming)顯(xian)，可(ke)(ke)(ke)改用(yong)R×1Ω檔來測(ce)(ce)(ce)），一般正(zheng)(zheng)向(xiang)電(dian)(dian)阻(zu)(zu)(zu)在(zai)(zai)R×10Ω檔測(ce)(ce)(ce)時(shi)(shi)表針應指(zhi)示在(zai)(zai)200Ω左右，在(zai)(zai)R×1Ω檔測(ce)(ce)(ce)時(shi)(shi)表針應指(zhi)示在(zai)(zai)30Ω左右（根據不(bu)同表型可(ke)(ke)(ke)能(neng)(neng)略(lve)有出(chu)入）。如(ru)(ru)果測(ce)(ce)(ce)量結果正(zheng)(zheng)向(xiang)阻(zu)(zu)(zu)值太大(da)或(huo)反(fan)向(xiang)阻(zu)(zu)(zu)值太小，都說(shuo)明(ming)這個(ge)PN結有問題(ti)，這個(ge)管(guan)(guan)子也就(jiu)有問題(ti)了。這種方法對于維修時(shi)(shi)特(te)別有效，可(ke)(ke)(ke)以(yi)(yi)(yi)非(fei)常快速地找出(chu)壞管(guan)(guan)，甚至可(ke)(ke)(ke)以(yi)(yi)(yi)測(ce)(ce)(ce)出(chu)尚未完全壞掉但(dan)特(te)性變壞的(de)管(guan)(guan)子。比(bi)如(ru)(ru)當你用(yong)小阻(zu)(zu)(zu)值檔測(ce)(ce)(ce)量某個(ge)PN結正(zheng)(zheng)向(xiang)電(dian)(dian)阻(zu)(zu)(zu)過大(da)，如(ru)(ru)果你把它焊下(xia)來用(yong)常用(yong)的(de)R×1kΩ檔再測(ce)(ce)(ce)，可(ke)(ke)(ke)能(neng)(neng)還是正(zheng)(zheng)常的(de)，其(qi)實(shi)這個(ge)管(guan)(guan)子的(de)特(te)性已(yi)經變壞了，不(bu)能(neng)(neng)正(zheng)(zheng)常工作(zuo)或(huo)不(bu)穩定了。

4、測電阻(zu)：重要(yao)的(de)是(shi)要(yao)選(xuan)好(hao)量(liang)程(cheng)，當指針指示于1/3～2/3滿量(liang)程(cheng)時測量(liang)精(jing)度最(zui)高，讀數(shu)最(zui)準確。要(yao)注意的(de)是(shi)，在用R×10k電阻(zu)檔測兆歐(ou)級的(de)大阻(zu)值(zhi)電阻(zu)時，不可將手指捏在電阻(zu)兩端，這樣人體電阻(zu)會(hui)使測量(liang)結果偏(pian)小。

5、測(ce)(ce)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)二極(ji)管(guan)(guan)(guan)(guan)：我(wo)(wo)們(men)通常所用(yong)(yong)(yong)(yong)到的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)一般都大(da)(da)(da)于1.5V，而(er)指針(zhen)表(biao)(biao)(biao)的(de)(de)(de)(de)R×1k以下(xia)(xia)的(de)(de)(de)(de)電(dian)(dian)阻(zu)檔是(shi)用(yong)(yong)(yong)(yong)表(biao)(biao)(biao)內的(de)(de)(de)(de)1.5V電(dian)(dian)池供(gong)電(dian)(dian)的(de)(de)(de)(de)，這(zhe)(zhe)樣(yang)，用(yong)(yong)(yong)(yong)R×1k以下(xia)(xia)的(de)(de)(de)(de)電(dian)(dian)阻(zu)檔測(ce)(ce)量穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)就(jiu)(jiu)(jiu)如(ru)同測(ce)(ce)二極(ji)管(guan)(guan)(guan)(guan)一樣(yang)，具(ju)有完全的(de)(de)(de)(de)單(dan)向(xiang)導電(dian)(dian)性(xing)。但(dan)指針(zhen)表(biao)(biao)(biao)的(de)(de)(de)(de)R×10k檔是(shi)用(yong)(yong)(yong)(yong)9V或15V電(dian)(dian)池供(gong)電(dian)(dian)的(de)(de)(de)(de)，在(zai)用(yong)(yong)(yong)(yong)R×10k測(ce)(ce)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)小(xiao)于9V或15V的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)時(shi)，反向(xiang)阻(zu)值(zhi)(zhi)(zhi)就(jiu)(jiu)(jiu)不(bu)會(hui)是(shi)∞，而(er)是(shi)有一定阻(zu)值(zhi)(zhi)(zhi)，但(dan)這(zhe)(zhe)個(ge)(ge)阻(zu)值(zhi)(zhi)(zhi)還是(shi)要大(da)(da)(da)大(da)(da)(da)高于穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)正向(xiang)阻(zu)值(zhi)(zhi)(zhi)的(de)(de)(de)(de)。如(ru)此，我(wo)(wo)們(men)就(jiu)(jiu)(jiu)可以初(chu)步估測(ce)(ce)出穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)好(hao)壞(huai)。但(dan)是(shi)，好(hao)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)還要有個(ge)(ge)準確的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)，業余條(tiao)件下(xia)(xia)怎(zen)么(me)估測(ce)(ce)出這(zhe)(zhe)個(ge)(ge)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)呢？不(bu)難，再去(qu)找一塊(kuai)指針(zhen)表(biao)(biao)(biao)來就(jiu)(jiu)(jiu)可以了(le)。方(fang)法(fa)是(shi)：先將(jiang)一塊(kuai)表(biao)(biao)(biao)置于R×10k檔，其黑、紅(hong)表(biao)(biao)(biao)筆分別(bie)接(jie)在(zai)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)陰(yin)極(ji)和陽極(ji)，這(zhe)(zhe)時(shi)就(jiu)(jiu)(jiu)模擬出穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)實際工作狀(zhuang)態，再取另一塊(kuai)表(biao)(biao)(biao)置于電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)檔V×10V或V×50V（根據穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)）上，將(jiang)紅(hong)、黑表(biao)(biao)(biao)筆分別(bie)搭接(jie)到剛才那(nei)塊(kuai)表(biao)(biao)(biao)的(de)(de)(de)(de)的(de)(de)(de)(de)黑、紅(hong)表(biao)(biao)(biao)筆上，這(zhe)(zhe)時(shi)測(ce)(ce)出的(de)(de)(de)(de)電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)就(jiu)(jiu)(jiu)基(ji)本上是(shi)這(zhe)(zhe)個(ge)(ge)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)。說“基(ji)本上”，是(shi)因為第一塊(kuai)表(biao)(biao)(biao)對(dui)(dui)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)偏(pian)置電(dian)(dian)流相對(dui)(dui)正常使(shi)用(yong)(yong)(yong)(yong)時(shi)的(de)(de)(de)(de)偏(pian)置電(dian)(dian)流稍小(xiao)些(xie)，所以測(ce)(ce)出的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)會(hui)稍偏(pian)大(da)(da)(da)一點，但(dan)基(ji)本相差(cha)不(bu)大(da)(da)(da)。這(zhe)(zhe)個(ge)(ge)方(fang)法(fa)只(zhi)可估測(ce)(ce)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)小(xiao)于指針(zhen)表(biao)(biao)(biao)高壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)電(dian)(dian)池電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)。如(ru)果穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)管(guan)(guan)(guan)(guan)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)值(zhi)(zhi)(zhi)太(tai)高，就(jiu)(jiu)(jiu)只(zhi)能(neng)用(yong)(yong)(yong)(yong)外加(jia)電(dian)(dian)源的(de)(de)(de)(de)方(fang)法(fa)來測(ce)(ce)量了(le)（這(zhe)(zhe)樣(yang)看來，我(wo)(wo)們(men)在(zai)選用(yong)(yong)(yong)(yong)指針(zhen)表(biao)(biao)(biao)時(shi)，選用(yong)(yong)(yong)(yong)高壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)電(dian)(dian)池電(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)(ya)(ya)為15V的(de)(de)(de)(de)要比9V的(de)(de)(de)(de)更適(shi)用(yong)(yong)(yong)(yong)些(xie)）。

6、測(ce)(ce)(ce)三(san)極管(guan)(guan)(guan)(guan)(guan)：通(tong)(tong)常我們要用R×1kΩ檔，不(bu)管(guan)(guan)(guan)(guan)(guan)是(shi)(shi)NPN管(guan)(guan)(guan)(guan)(guan)還(huan)是(shi)(shi)PNP管(guan)(guan)(guan)(guan)(guan)，不(bu)管(guan)(guan)(guan)(guan)(guan)是(shi)(shi)小(xiao)功(gong)(gong)率、中(zhong)功(gong)(gong)率、大(da)(da)功(gong)(gong)率管(guan)(guan)(guan)(guan)(guan)，測(ce)(ce)(ce)其be結(jie)cb結(jie)都(dou)(dou)應(ying)(ying)(ying)呈現與二極管(guan)(guan)(guan)(guan)(guan)完全(quan)相同的(de)(de)(de)單向(xiang)(xiang)導(dao)電(dian)(dian)(dian)性(xing)(xing)，反(fan)向(xiang)(xiang)電(dian)(dian)(dian)阻無(wu)窮大(da)(da)，其正向(xiang)(xiang)電(dian)(dian)(dian)阻大(da)(da)約(yue)在(zai)10K左右(you)。為(wei)進(jin)(jin)一步估測(ce)(ce)(ce)管(guan)(guan)(guan)(guan)(guan)子(zi)特性(xing)(xing)的(de)(de)(de)好(hao)壞，必(bi)要時(shi)還(huan)應(ying)(ying)(ying)變(bian)換電(dian)(dian)(dian)阻檔位進(jin)(jin)行多次測(ce)(ce)(ce)量(liang)，方法是(shi)(shi)：置(zhi)(zhi)R×10Ω檔測(ce)(ce)(ce)PN結(jie)正向(xiang)(xiang)導(dao)通(tong)(tong)電(dian)(dian)(dian)阻都(dou)(dou)在(zai)大(da)(da)約(yue)200Ω左右(you)；置(zhi)(zhi)R×1Ω檔測(ce)(ce)(ce)PN結(jie)正向(xiang)(xiang)導(dao)通(tong)(tong)電(dian)(dian)(dian)阻都(dou)(dou)在(zai)大(da)(da)約(yue)30Ω左右(you)，（以(yi)上為(wei)47型(xing)表(biao)測(ce)(ce)(ce)得數據(ju)，其它型(xing)號表(biao)大(da)(da)概略有不(bu)同，可(ke)(ke)多試測(ce)(ce)(ce)幾個好(hao)管(guan)(guan)(guan)(guan)(guan)總結(jie)一下，做到心中(zhong)有數）如果讀數偏大(da)(da)太多，可(ke)(ke)以(yi)斷定(ding)管(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)特性(xing)(xing)不(bu)好(hao)。還(huan)可(ke)(ke)將表(biao)置(zhi)(zhi)于R×10kΩ再(zai)測(ce)(ce)(ce)，耐壓(ya)再(zai)低的(de)(de)(de)管(guan)(guan)(guan)(guan)(guan)子(zi)（基本上三(san)極管(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)耐壓(ya)都(dou)(dou)在(zai)30V以(yi)上），其cb結(jie)反(fan)向(xiang)(xiang)電(dian)(dian)(dian)阻也(ye)應(ying)(ying)(ying)在(zai)∞，但其be結(jie)的(de)(de)(de)反(fan)向(xiang)(xiang)電(dian)(dian)(dian)阻可(ke)(ke)能(neng)會(hui)有些，表(biao)針會(hui)稍有偏轉(zhuan)（一般不(bu)會(hui)超過滿(man)量(liang)程的(de)(de)(de)1/3，根據(ju)管(guan)(guan)(guan)(guan)(guan)子(zi)的(de)(de)(de)耐壓(ya)不(bu)同而(er)不(bu)同）。同樣(yang)，在(zai)用R×10kΩ檔測(ce)(ce)(ce)ec間(jian)(jian)(對(dui)(dui)NPN管(guan)(guan)(guan)(guan)(guan)）或(huo)ce間(jian)(jian)（對(dui)(dui)PNP管(guan)(guan)(guan)(guan)(guan)）的(de)(de)(de)電(dian)(dian)(dian)阻時(shi)，表(biao)針可(ke)(ke)能(neng)略有偏轉(zhuan)，但這不(bu)表(biao)示管(guan)(guan)(guan)(guan)(guan)子(zi)是(shi)(shi)壞的(de)(de)(de)。但在(zai)用R×1kΩ以(yi)下檔測(ce)(ce)(ce)ce或(huo)ec間(jian)(jian)電(dian)(dian)(dian)阻時(shi)，表(biao)頭指示應(ying)(ying)(ying)為(wei)無(wu)窮大(da)(da)，否則管(guan)(guan)(guan)(guan)(guan)子(zi)就是(shi)(shi)有問(wen)題。應(ying)(ying)(ying)該說明(ming)一點的(de)(de)(de)是(shi)(shi)，以(yi)上測(ce)(ce)(ce)量(liang)是(shi)(shi)針對(dui)(dui)硅管(guan)(guan)(guan)(guan)(guan)而(er)言(yan)的(de)(de)(de)，對(dui)(dui)鍺(zang)管(guan)(guan)(guan)(guan)(guan)不(bu)適用。不(bu)過現在(zai)鍺(zang)管(guan)(guan)(guan)(guan)(guan)也(ye)很少見了。另外，所說的(de)(de)(de)“反(fan)向(xiang)(xiang)”是(shi)(shi)針對(dui)(dui)PN結(jie)而(er)言(yan)，對(dui)(dui)NPN管(guan)(guan)(guan)(guan)(guan)和PNP管(guan)(guan)(guan)(guan)(guan)方向(xiang)(xiang)實際(ji)上是(shi)(shi)不(bu)同的(de)(de)(de)。