【萬能表】萬能表的使用方法 電(dian)工用的(de)萬能表的(de)使用方法(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)阻檔(dang)(dang)，指針(zhen)表的(de)表筆輸出電(dian)流相對數字表來說(shuo)要(yao)大很多，用(yong)R×1Ω檔(dang)(dang)可以(yi)使揚聲(sheng)(sheng)器發出響(xiang)亮(liang)的(de)“噠(da)”聲(sheng)(sheng)，用(yong)R×10kΩ檔(dang)(dang)甚(shen)至可以(yi)點(dian)亮(liang)發光二極(ji)管(guan)（LED）。

3、在(zai)電(dian)壓(ya)檔，指針表(biao)內(nei)(nei)(nei)阻(zu)相(xiang)對(dui)(dui)數字表(biao)來說比較(jiao)小，測量精(jing)度相(xiang)比較(jiao)差。某些高電(dian)壓(ya)微電(dian)流的(de)(de)場合甚至(zhi)無法(fa)測準(zhun)，因(yin)為其(qi)內(nei)(nei)(nei)阻(zu)會對(dui)(dui)被(bei)測電(dian)路造成影(ying)響(xiang)(xiang)（比如在(zai)測電(dian)視機顯(xian)像管(guan)的(de)(de)加速級電(dian)壓(ya)時測量值會比實際值低很多）。數字表(biao)電(dian)壓(ya)檔的(de)(de)內(nei)(nei)(nei)阻(zu)很大，至(zhi)少在(zai)兆歐級，對(dui)(dui)被(bei)測電(dian)路影(ying)響(xiang)(xiang)很小。但(dan)極高的(de)(de)輸出阻(zu)抗(kang)使其(qi)易受感應電(dian)壓(ya)的(de)(de)影(ying)響(xiang)(xiang)，在(zai)一些電(dian)磁干擾比較(jiao)強(qiang)的(de)(de)場合測出的(de)(de)數據可能是虛的(de)(de)。

4、總之，在相對(dui)來說(shuo)大電(dian)(dian)流(liu)高電(dian)(dian)壓(ya)的模擬電(dian)(dian)路測量中(zhong)(zhong)適用指針表(biao)(biao)，比(bi)如電(dian)(dian)視機(ji)、音響功放。在低電(dian)(dian)壓(ya)小電(dian)(dian)流(liu)的數字(zi)電(dian)(dian)路測量中(zhong)(zhong)適用數字(zi)表(biao)(biao)，比(bi)如BP機(ji)、手(shou)機(ji)等。不是絕(jue)對(dui)的，可根據情況選用指針表(biao)(biao)和數字(zi)表(biao)(biao)。

二、測量技巧（如不作說明，則指用的是指針表）：

1、測喇叭、耳機、動圈(quan)式話(hua)筒：用R×1Ω檔，任一表筆接一端(duan)，另一表筆點觸另一端(duan)，正常時會發(fa)出清(qing)脆響量的“噠”聲(sheng)。如(ru)(ru)果不響，則是線圈(quan)斷了(le)，如(ru)(ru)果響聲(sheng)小而尖(jian)，則是有(you)擦圈(quan)問題，也不能用。

2、測(ce)(ce)(ce)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)：用(yong)(yong)電(dian)(dian)阻檔(dang)，根據電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)選(xuan)擇適當的(de)(de)(de)(de)(de)量(liang)(liang)(liang)程，并注(zhu)意測(ce)(ce)(ce)量(liang)(liang)(liang)時(shi)(shi)對于電(dian)(dian)解電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)黑表筆要(yao)(yao)接(jie)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)正極。①、估測(ce)(ce)(ce)微波法(fa)(fa)級電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)的(de)(de)(de)(de)(de)大(da)(da)小(xiao)：可(ke)(ke)憑經(jing)驗(yan)或參(can)照(zhao)相同容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)的(de)(de)(de)(de)(de)標準電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)，根據指針(zhen)擺動的(de)(de)(de)(de)(de)最(zui)大(da)(da)幅度來(lai)判定(ding)。所參(can)照(zhao)的(de)(de)(de)(de)(de)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)不(bu)必耐壓值也(ye)一樣(yang)(yang)，只(zhi)要(yao)(yao)容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)相同即可(ke)(ke)，例如(ru)估測(ce)(ce)(ce)一個(ge)(ge)100μF/250V的(de)(de)(de)(de)(de)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)可(ke)(ke)用(yong)(yong)一個(ge)(ge)100μF/25V的(de)(de)(de)(de)(de)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)來(lai)參(can)照(zhao)，只(zhi)要(yao)(yao)它們指針(zhen)擺動最(zui)大(da)(da)幅度一樣(yang)(yang)，即可(ke)(ke)斷定(ding)容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)一樣(yang)(yang)。②、估測(ce)(ce)(ce)皮法(fa)(fa)級電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)大(da)(da)小(xiao)：要(yao)(yao)用(yong)(yong)R×10kΩ檔(dang)，但只(zhi)能(neng)測(ce)(ce)(ce)到(dao)1000pF以上的(de)(de)(de)(de)(de)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)。對1000pF或稍(shao)大(da)(da)一點的(de)(de)(de)(de)(de)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)，只(zhi)要(yao)(yao)表針(zhen)稍(shao)有(you)擺動，即可(ke)(ke)認為容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)夠了。③、測(ce)(ce)(ce)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)是否(fou)漏(lou)電(dian)(dian)：對一千(qian)微法(fa)(fa)以上的(de)(de)(de)(de)(de)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)，可(ke)(ke)先用(yong)(yong)R×10Ω檔(dang)將其(qi)快速(su)充電(dian)(dian)，并初步估測(ce)(ce)(ce)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)容(rong)(rong)(rong)(rong)(rong)(rong)量(liang)(liang)(liang)，然后(hou)改到(dao)R×1kΩ檔(dang)繼續測(ce)(ce)(ce)一會兒，這時(shi)(shi)指針(zhen)不(bu)應(ying)回返，而應(ying)停在(zai)或十(shi)(shi)分接(jie)近∞處，否(fou)則就是有(you)漏(lou)電(dian)(dian)現象。對一些幾(ji)十(shi)(shi)微法(fa)(fa)以下的(de)(de)(de)(de)(de)定(ding)時(shi)(shi)或振蕩(dang)(dang)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)（比如(ru)彩(cai)電(dian)(dian)開(kai)關電(dian)(dian)源的(de)(de)(de)(de)(de)振蕩(dang)(dang)電(dian)(dian)容(rong)(rong)(rong)(rong)(rong)(rong)），對其(qi)漏(lou)電(dian)(dian)特性要(yao)(yao)求(qiu)非常高，只(zhi)要(yao)(yao)稍(shao)有(you)漏(lou)電(dian)(dian)就不(bu)能(neng)用(yong)(yong)，這時(shi)(shi)可(ke)(ke)在(zai)R×1kΩ檔(dang)充完電(dian)(dian)后(hou)再(zai)改用(yong)(yong)R×10kΩ檔(dang)繼續測(ce)(ce)(ce)量(liang)(liang)(liang)，同樣(yang)(yang)表針(zhen)應(ying)停在(zai)∞處而不(bu)應(ying)回返。

3、在(zai)(zai)(zai)(zai)路測(ce)二極管、三(san)極管、穩(wen)壓(ya)管好壞(huai)：因(yin)為(wei)在(zai)(zai)(zai)(zai)實際電(dian)路中，三(san)極管的(de)(de)(de)(de)偏置(zhi)電(dian)阻(zu)(zu)或(huo)二極管、穩(wen)壓(ya)管的(de)(de)(de)(de)周邊電(dian)阻(zu)(zu)一般(ban)都比較大(da)(da)，大(da)(da)都在(zai)(zai)(zai)(zai)幾(ji)百幾(ji)千(qian)歐姆以(yi)上，這(zhe)樣，我們就可以(yi)用萬用表的(de)(de)(de)(de)R×10Ω或(huo)R×1Ω檔(dang)來(lai)(lai)在(zai)(zai)(zai)(zai)路測(ce)量(liang)PN結(jie)的(de)(de)(de)(de)好壞(huai)。在(zai)(zai)(zai)(zai)路測(ce)量(liang)時(shi)，用R×10Ω檔(dang)測(ce)PN結(jie)應(ying)有(you)(you)較明(ming)顯(xian)的(de)(de)(de)(de)正(zheng)(zheng)(zheng)(zheng)反(fan)向特(te)性(xing)（如(ru)果(guo)正(zheng)(zheng)(zheng)(zheng)反(fan)向電(dian)阻(zu)(zu)相(xiang)差不太(tai)明(ming)顯(xian)，可改用R×1Ω檔(dang)來(lai)(lai)測(ce)），一般(ban)正(zheng)(zheng)(zheng)(zheng)向電(dian)阻(zu)(zu)在(zai)(zai)(zai)(zai)R×10Ω檔(dang)測(ce)時(shi)表針(zhen)應(ying)指示在(zai)(zai)(zai)(zai)200Ω左右(you)，在(zai)(zai)(zai)(zai)R×1Ω檔(dang)測(ce)時(shi)表針(zhen)應(ying)指示在(zai)(zai)(zai)(zai)30Ω左右(you)（根(gen)據不同(tong)表型可能略有(you)(you)出入）。如(ru)果(guo)測(ce)量(liang)結(jie)果(guo)正(zheng)(zheng)(zheng)(zheng)向阻(zu)(zu)值(zhi)太(tai)大(da)(da)或(huo)反(fan)向阻(zu)(zu)值(zhi)太(tai)小(xiao)，都說(shuo)明(ming)這(zhe)個(ge)(ge)PN結(jie)有(you)(you)問題，這(zhe)個(ge)(ge)管子也就有(you)(you)問題了。這(zhe)種方(fang)法(fa)對(dui)于(yu)維修(xiu)時(shi)特(te)別(bie)有(you)(you)效，可以(yi)非常快速地找出壞(huai)管，甚至(zhi)可以(yi)測(ce)出尚未完(wan)全壞(huai)掉但特(te)性(xing)變壞(huai)的(de)(de)(de)(de)管子。比如(ru)當你(ni)用小(xiao)阻(zu)(zu)值(zhi)檔(dang)測(ce)量(liang)某(mou)個(ge)(ge)PN結(jie)正(zheng)(zheng)(zheng)(zheng)向電(dian)阻(zu)(zu)過大(da)(da)，如(ru)果(guo)你(ni)把它(ta)焊下來(lai)(lai)用常用的(de)(de)(de)(de)R×1kΩ檔(dang)再測(ce)，可能還是正(zheng)(zheng)(zheng)(zheng)常的(de)(de)(de)(de)，其實這(zhe)個(ge)(ge)管子的(de)(de)(de)(de)特(te)性(xing)已經變壞(huai)了，不能正(zheng)(zheng)(zheng)(zheng)常工作或(huo)不穩(wen)定了。

4、測(ce)(ce)電(dian)阻：重(zhong)要的是要選好量程，當(dang)指(zhi)針(zhen)指(zhi)示于1/3～2/3滿量程時(shi)測(ce)(ce)量精度最高，讀數最準確(que)。要注(zhu)意的是，在(zai)用R×10k電(dian)阻檔測(ce)(ce)兆歐(ou)級的大阻值電(dian)阻時(shi)，不可將(jiang)手指(zhi)捏在(zai)電(dian)阻兩端，這樣人體電(dian)阻會使測(ce)(ce)量結(jie)果偏(pian)小。

5、測(ce)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)二極(ji)管(guan)(guan)(guan)：我們(men)通常(chang)所(suo)用(yong)(yong)(yong)(yong)(yong)到(dao)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)一(yi)般(ban)都大(da)于(yu)(yu)1.5V，而指(zhi)針(zhen)表的(de)(de)(de)(de)R×1k以下的(de)(de)(de)(de)電(dian)(dian)(dian)阻(zu)(zu)檔(dang)是(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)表內的(de)(de)(de)(de)1.5V電(dian)(dian)(dian)池供(gong)電(dian)(dian)(dian)的(de)(de)(de)(de)，這(zhe)(zhe)(zhe)樣(yang)，用(yong)(yong)(yong)(yong)(yong)R×1k以下的(de)(de)(de)(de)電(dian)(dian)(dian)阻(zu)(zu)檔(dang)測(ce)量(liang)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)就(jiu)如(ru)同測(ce)二極(ji)管(guan)(guan)(guan)一(yi)樣(yang)，具(ju)有(you)(you)(you)完全的(de)(de)(de)(de)單(dan)向(xiang)導電(dian)(dian)(dian)性。但指(zhi)針(zhen)表的(de)(de)(de)(de)R×10k檔(dang)是(shi)(shi)(shi)用(yong)(yong)(yong)(yong)(yong)9V或15V電(dian)(dian)(dian)池供(gong)電(dian)(dian)(dian)的(de)(de)(de)(de)，在用(yong)(yong)(yong)(yong)(yong)R×10k測(ce)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)小于(yu)(yu)9V或15V的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)時(shi)，反向(xiang)阻(zu)(zu)值(zhi)(zhi)(zhi)就(jiu)不(bu)會是(shi)(shi)(shi)∞，而是(shi)(shi)(shi)有(you)(you)(you)一(yi)定阻(zu)(zu)值(zhi)(zhi)(zhi)，但這(zhe)(zhe)(zhe)個阻(zu)(zu)值(zhi)(zhi)(zhi)還是(shi)(shi)(shi)要大(da)大(da)高(gao)于(yu)(yu)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)正(zheng)向(xiang)阻(zu)(zu)值(zhi)(zhi)(zhi)的(de)(de)(de)(de)。如(ru)此，我們(men)就(jiu)可(ke)以初步估(gu)測(ce)出(chu)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)好(hao)壞。但是(shi)(shi)(shi)，好(hao)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)還要有(you)(you)(you)個準(zhun)確的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)，業余條件下怎么(me)估(gu)測(ce)出(chu)這(zhe)(zhe)(zhe)個穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)呢？不(bu)難，再(zai)去找一(yi)塊(kuai)(kuai)指(zhi)針(zhen)表來(lai)就(jiu)可(ke)以了。方法是(shi)(shi)(shi)：先將一(yi)塊(kuai)(kuai)表置于(yu)(yu)R×10k檔(dang)，其黑(hei)、紅表筆(bi)分(fen)別接(jie)在穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)陰極(ji)和陽極(ji)，這(zhe)(zhe)(zhe)時(shi)就(jiu)模擬出(chu)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)實際(ji)工作狀(zhuang)態，再(zai)取另一(yi)塊(kuai)(kuai)表置于(yu)(yu)電(dian)(dian)(dian)壓(ya)(ya)檔(dang)V×10V或V×50V（根據穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)）上，將紅、黑(hei)表筆(bi)分(fen)別搭接(jie)到(dao)剛才那塊(kuai)(kuai)表的(de)(de)(de)(de)的(de)(de)(de)(de)黑(hei)、紅表筆(bi)上，這(zhe)(zhe)(zhe)時(shi)測(ce)出(chu)的(de)(de)(de)(de)電(dian)(dian)(dian)壓(ya)(ya)值(zhi)(zhi)(zhi)就(jiu)基本上是(shi)(shi)(shi)這(zhe)(zhe)(zhe)個穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)。說“基本上”，是(shi)(shi)(shi)因為第一(yi)塊(kuai)(kuai)表對穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)偏置電(dian)(dian)(dian)流相(xiang)對正(zheng)常(chang)使(shi)用(yong)(yong)(yong)(yong)(yong)時(shi)的(de)(de)(de)(de)偏置電(dian)(dian)(dian)流稍(shao)小些(xie)，所(suo)以測(ce)出(chu)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)會稍(shao)偏大(da)一(yi)點，但基本相(xiang)差不(bu)大(da)。這(zhe)(zhe)(zhe)個方法只可(ke)估(gu)測(ce)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)小于(yu)(yu)指(zhi)針(zhen)表高(gao)壓(ya)(ya)電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)。如(ru)果穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)管(guan)(guan)(guan)的(de)(de)(de)(de)穩(wen)(wen)(wen)(wen)(wen)(wen)(wen)(wen)壓(ya)(ya)值(zhi)(zhi)(zhi)太高(gao)，就(jiu)只能用(yong)(yong)(yong)(yong)(yong)外(wai)加電(dian)(dian)(dian)源(yuan)的(de)(de)(de)(de)方法來(lai)測(ce)量(liang)了（這(zhe)(zhe)(zhe)樣(yang)看來(lai)，我們(men)在選(xuan)用(yong)(yong)(yong)(yong)(yong)指(zhi)針(zhen)表時(shi)，選(xuan)用(yong)(yong)(yong)(yong)(yong)高(gao)壓(ya)(ya)電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)(ya)為15V的(de)(de)(de)(de)要比9V的(de)(de)(de)(de)更適用(yong)(yong)(yong)(yong)(yong)些(xie)）。

6、測(ce)(ce)(ce)(ce)三(san)極管(guan)(guan)(guan)(guan)(guan)：通常我們要(yao)用(yong)(yong)R×1kΩ檔(dang)，不(bu)管(guan)(guan)(guan)(guan)(guan)是(shi)(shi)(shi)(shi)NPN管(guan)(guan)(guan)(guan)(guan)還(huan)是(shi)(shi)(shi)(shi)PNP管(guan)(guan)(guan)(guan)(guan)，不(bu)管(guan)(guan)(guan)(guan)(guan)是(shi)(shi)(shi)(shi)小功(gong)率、中功(gong)率、大(da)(da)功(gong)率管(guan)(guan)(guan)(guan)(guan)，測(ce)(ce)(ce)(ce)其be結(jie)(jie)(jie)cb結(jie)(jie)(jie)都(dou)(dou)應(ying)呈現與二極管(guan)(guan)(guan)(guan)(guan)完全相同的單向(xiang)導(dao)電(dian)性(xing)(xing)(xing)，反(fan)(fan)(fan)向(xiang)電(dian)阻無(wu)窮大(da)(da)，其正向(xiang)電(dian)阻大(da)(da)約在(zai)10K左右(you)(you)。為進一(yi)步估測(ce)(ce)(ce)(ce)管(guan)(guan)(guan)(guan)(guan)子(zi)特性(xing)(xing)(xing)的好(hao)壞，必要(yao)時(shi)還(huan)應(ying)變換電(dian)阻檔(dang)位進行多次測(ce)(ce)(ce)(ce)量(liang)，方(fang)(fang)法是(shi)(shi)(shi)(shi)：置(zhi)R×10Ω檔(dang)測(ce)(ce)(ce)(ce)PN結(jie)(jie)(jie)正向(xiang)導(dao)通電(dian)阻都(dou)(dou)在(zai)大(da)(da)約200Ω左右(you)(you)；置(zhi)R×1Ω檔(dang)測(ce)(ce)(ce)(ce)PN結(jie)(jie)(jie)正向(xiang)導(dao)通電(dian)阻都(dou)(dou)在(zai)大(da)(da)約30Ω左右(you)(you)，（以(yi)(yi)上為47型表(biao)測(ce)(ce)(ce)(ce)得數據(ju)，其它型號表(biao)大(da)(da)概略有(you)不(bu)同，可(ke)多試(shi)測(ce)(ce)(ce)(ce)幾個好(hao)管(guan)(guan)(guan)(guan)(guan)總結(jie)(jie)(jie)一(yi)下，做到(dao)心中有(you)數）如果讀數偏(pian)大(da)(da)太多，可(ke)以(yi)(yi)斷定管(guan)(guan)(guan)(guan)(guan)子(zi)的特性(xing)(xing)(xing)不(bu)好(hao)。還(huan)可(ke)將表(biao)置(zhi)于R×10kΩ再測(ce)(ce)(ce)(ce)，耐壓(ya)再低的管(guan)(guan)(guan)(guan)(guan)子(zi)（基本上三(san)極管(guan)(guan)(guan)(guan)(guan)的耐壓(ya)都(dou)(dou)在(zai)30V以(yi)(yi)上），其cb結(jie)(jie)(jie)反(fan)(fan)(fan)向(xiang)電(dian)阻也(ye)應(ying)在(zai)∞，但(dan)(dan)其be結(jie)(jie)(jie)的反(fan)(fan)(fan)向(xiang)電(dian)阻可(ke)能會有(you)些，表(biao)針會稍有(you)偏(pian)轉（一(yi)般(ban)不(bu)會超過滿量(liang)程的1/3，根據(ju)管(guan)(guan)(guan)(guan)(guan)子(zi)的耐壓(ya)不(bu)同而不(bu)同）。同樣，在(zai)用(yong)(yong)R×10kΩ檔(dang)測(ce)(ce)(ce)(ce)ec間(對(dui)NPN管(guan)(guan)(guan)(guan)(guan)）或ce間（對(dui)PNP管(guan)(guan)(guan)(guan)(guan)）的電(dian)阻時(shi)，表(biao)針可(ke)能略有(you)偏(pian)轉，但(dan)(dan)這不(bu)表(biao)示管(guan)(guan)(guan)(guan)(guan)子(zi)是(shi)(shi)(shi)(shi)壞的。但(dan)(dan)在(zai)用(yong)(yong)R×1kΩ以(yi)(yi)下檔(dang)測(ce)(ce)(ce)(ce)ce或ec間電(dian)阻時(shi)，表(biao)頭指(zhi)示應(ying)為無(wu)窮大(da)(da)，否則管(guan)(guan)(guan)(guan)(guan)子(zi)就(jiu)是(shi)(shi)(shi)(shi)有(you)問題(ti)。應(ying)該說明(ming)一(yi)點(dian)的是(shi)(shi)(shi)(shi)，以(yi)(yi)上測(ce)(ce)(ce)(ce)量(liang)是(shi)(shi)(shi)(shi)針對(dui)硅管(guan)(guan)(guan)(guan)(guan)而言的，對(dui)鍺管(guan)(guan)(guan)(guan)(guan)不(bu)適用(yong)(yong)。不(bu)過現在(zai)鍺管(guan)(guan)(guan)(guan)(guan)也(ye)很少見了。另(ling)外，所(suo)說的“反(fan)(fan)(fan)向(xiang)”是(shi)(shi)(shi)(shi)針對(dui)PN結(jie)(jie)(jie)而言，對(dui)NPN管(guan)(guan)(guan)(guan)(guan)和PNP管(guan)(guan)(guan)(guan)(guan)方(fang)(fang)向(xiang)實際(ji)上是(shi)(shi)(shi)(shi)不(bu)同的。